Comparison of Active, Passive, and Proprioceptive Neuromuscular Facilitation Stretching for Improving Glenohumeral Internal Rotation.
- J Hall, G D Oliver, and A J Stone
Athletic Training and Sports Health Care, July/August 2012 – Volume 4 · Issue 4: 181-188
The purpose of this study was to compare the effectiveness of active, passive, and proprioceptive neuromuscular facilitation (PNF) stretching techniques on improving internal rotation of the shoulder in asymptomatic individuals. From a convenience sample of college students, including individuals on a particular athletic team, 42 asymptomatic individuals volunteered to participate. A stretching intervention was implemented during which participants performed 3 shoulder stretches by either passive, active, or PNF techniques. The results revealed significant differences in range of motion (ROM) over time for internal rotation among the different stretching protocols (P < .01). However, the stretching protocol implemented, whether passive, active, or PNF, did not significantly affect ROM for internal rotation. The current findings revealed that active, passive, and PNF stretching over time can elicit increases in internal rotation within the glenohumeral joint, and these changes are apparent after 1 week of stretching intervention.
A Comparison of Assisted and Unassisted Proprioceptive Neuromuscular Facilitation Techniques and Static Stretching.
- Meaghan E Maddigan, Ashley A Peach, and David G Behm
Journal of Strength and Conditioning Research, 2012 vol. 26 (5) pp. 1238-1244
Proprioceptive neuromuscular facilitation (PNF) stretching often requires a partner. Straps are available allowing an individual to perform PNF stretching alone. It is not known if a strap provides similar improvements in the range of motion (ROM) as partner-assisted PNF or static stretching. The purpose of this study was to compare assisted and unassisted (with a strap) PNF stretching and static stretching. Hip joint ROM, reaction time (RT), and movement time (MT) were measured prestretching and poststretching. Thirteen recreationally active adults participated in this study. The participants were subjected to 5 different stretch interventions in a random order on separate days. Stretch conditions included unassisted PNF stretching using (a) isometric, (b) concentric, and (c) eccentric contractions with a stretch strap, (d) partner-assisted isometric PNF, and (e) static stretching. The RT, MT, dynamic, active, passive hip flexion angle, and angular velocity with dynamic hip flexion were measured before and after the intervention. The ROM improved (p < 0.05) 2.6, 2.7, and 5.4%, respectively, with dynamic, active static, and passive static ROM, but there was no significant difference between the stretching protocols. There was a main effect for time (p < 0.05) with all stretching conditions negatively impacting dynamic angular velocity (9.2%). Although there was no significant effect on RT, MT showed a negative main effect for time (p < 0.05) slowing 3.4%. In conclusion, it was found that all 3 forms of active stretching provided similar improvements in the ROM and poststretching performance decrements in MT and angular velocity. Thus, individuals can implement PNF stretching techniques with a partner or alone with a strap to improve ROM, but athletes should not use these techniques before important competitions or training because of the impairment of limb velocity and MT.
A Comparative Study On The Effect Of Resistance Training And Pnf To Improve Balance In Parkinson’s Patients – A Randomized Clinical Trial.
- Arpita Christanand Gholap
Background and objectives- Disorders of posture and gait due to balance impairment are a major source of functional disability in individuals with Parkinson’s disease ( PD) . Fear of fall is commonly seen in PD patients. Regular physical exercise therapy can be beneficial to maintain and improve strength, balance, gait speed and quality of life in PD patients. The objective is to study and compare the effectiveness of Resistance Training and PNF in subjects with Parkinson’s disease. Materials and methods- Total of 30 participants between age of 40 to 70 years, having Parkinson’s disease were recruited in this study. The participants were allocated into 2 groups viz., Group A ( Resistance training) and Group B ( PNF ) and treated with of Resistance training and Proprioceptive Neuromuscular Facilitation ( PNF ) technique with a common treatment of balance training for specific balance impairments for 16 sessions over a period of 4 weeks. Outcome measures were Timed up and Go ( TUG) test and Berg Balance Scale score ( BBS ) which were assessed before and after the intervention session. Results- The results showed improvement in balance for both the groups A and B. But, there was better improvement in balance for berg balance scale ( BBS ) score ( p= 0.052 ) and timed up & go ( TUG) test ( p=0.819 ) in resistance training group than PNF group. vi Conclusion- Resistance training is more effective as compared with Proprioceptive Neuromuscular Facilitation ( PNF ) technique in improving balance in Parkinson’s disease patients.
Acute Effects of Static and Proprioceptive Neuromuscular Facilitation Stretching on Agility Performance in Elite Youth Soccer Players.
- J B Jordan and A D Korgaokar
Int J Exerc Sci 5(2) : 97-105, 2012
A warm-up is an important part of preparation for a soccer match. Stretching is typically part of the warm-up however, debate exists as to the most appropriate type of stretching to perform. The purpose of this study was to examine the effects of static and proprioceptive neuromuscular facilitation (PNF) stretching on soccer-specific agility performance in 14 male elite, premier league youth soccer players. Participants completed 4 trials of the Balsom agility test while dribbling a soccer ball. Height, age, and body mass were collected in trial 1 and participants were accommodated to the agility test during trials 1 and 2. Trials 3 and 4 were the static and PNF treatment trials that were administered after a standardized warm-up (control) in a randomized and counterbalanced manner. There were no significant differences between the difference scores of the static and PNF stretching conditions, P = .66. Furthermore, no significant differences were found between the control and stretching trials for static stretching, P = .15 or between the control and stretching trials for PNF stretching, P = .58. Neither mode of stretching significantly affected agility performance. More research is needed to determine the chronic effects of PNF stretching on agility performance.
Efficacy of Pnf Stretching Techniques on Hamstring Tightness in Young Male Adult Population.
- A Zakaria, G R Melam, and S Buragadda
World Journal of Medical Sciences, 2012
To find out the efficacy of different PNF stretching techniques in improving Hamstring muscle flexibility.Study Design included pre- post test control group design. Participants were 30 male students from King Saud University between the age group of 18 to 24 years having Hamstring tightness and without any musculoskeletal disorders formed the sample of this study. Subject’s age, height and weight were matched. Informed consent was taken from all the subjects. Group I acts as a Control group consisting of 15 subjects who receives Self stretch Group II acts as a Experimental group consisting of 15 subjects who receives Therapist PNF stretch. Outcome Measures included straight leg raising test (SLRT) measured by Universal goniometer..Results revealed that both the groups performed stretching 5 times a week for 6 weeks. Four repetitions per session with relaxation period of 15 sec and stretch period of 15 sec. Pre test and Post test values of the Control group and Experimental group were statistically analyzed by means of t-test.The Post test values of Experimental and Control group were analyzed by Chi square test ( 2 test). The Significance level used for this study is P<0.05. This study concluded that though statistically there is no significant difference between self stretch and therapist applied PNF stretch, both are effective treatment methods but Therapist applied PNF stretch is clinically more significant over self stretch.
Proprioceptive Neuromuscular Facilitation (PNF): Its Mechanisms and Effects on Range of Motion and Muscular Function.
- K B Hindle, T J Whitcomb, W O Briggs, and J Hong
Journal of Human Kinetics, 2012
Proprioceptive neuromuscular facilitation (PNF) is common practice for increasing range of motion, though little research has been done to evaluate theories behind it. The purpose of this study was to review possible mechanisms, proposed theories, and physiological changes that occur due to proprioceptive neuromuscular facilitation techniques. Four theoretical mechanisms were identified: autogenic inhibition, reciprocal inhibition, stress relaxation, and the gate control theory. The studies suggest that a combination of these four mechanisms enhance range of motion. When completed prior to exercise, proprioceptive neuromuscular facilitation decreases performance in maximal effort exercises. When this stretching technique is performed consistently and post exercise, it increases athletic performance, along with range of motion. Little investigation has been done regarding the theoretical mechanisms of proprioceptive neuromuscular facilitation, though four mechanisms were identified from the literature. As stated, the main goal of proprioceptive neuromuscular facilitation is to increase range of motion and performance. Studies found both of these to be true when completed under the correct conditions. These mechanisms were found to be plausible; however, further investigation needs to be conducted. All four mechanisms behind the stretching technique explain the reasoning behind the increase in range of motion, as well as in strength and athletic performance. Proprioceptive neuromuscular facilitation shows potential benefits if performed correctly and consistently.
A prophylactic effect of proprioceptive neuromuscular facilitation (PNF) stretching on symptoms of muscle damage induced by eccentric exercise of the wrist extensors.
- P Khamwong, U Pirunsan, and A Paungmali
J Bodyw Mov Ther. 2011 Oct;15(4):507-16.
Stretching with proprioceptive neuromuscular facilitation (PNF) is frequently used before exercise. The prophylactic effect of PNF on symptoms of muscle damage induced by eccentric exercise of the wrist extensors was examined in this study. Twenty-eight healthy males were randomly divided into the PNF group (n = 14) and the control group (n = 14). PNF was used before eccentric exercise induction in the wrist extensors. All subjects were tested to examine muscle damage characteristics including sensory-motor functions at baseline, immediately, and from 1st to 8th days after the exercise-induced muscle damage (EIMD). The results demonstrated that the PNF group showed a lesser deficit in some sensory-motor functions (p < 0.05) than the control group. The prior PNF stretching application could be useful for attenuating the signs and symptoms of muscle damage after eccentric exercise.
Efficacy of static stretching and proprioceptive neuromuscular facilitation stretch on hamstrings length after a single session.
- O’Hora J, Cartwright A, Wade CD, Hough AD, Shum GL.
J Strength Cond Res. 2011 Jun;25(6):1586-91.
A number of studies have investigated the efficacy of several repetitions of proprioceptive neuromuscular facilitation stretching (PNF) and static stretching (SS). However, there is limited research comparing the effects of a single bout of these stretching maneuvers. The aim of this study was to compare the effectiveness of a single bout of a therapist-applied 30-second SS vs. a single bout of therapist-applied 6-second hamstring (agonist) contract PNF. Forty-five healthy subjects between the ages of 21 and 35 were randomly allocated to 1 of the 2 stretching groups or a control group, in which no stretching was received. The flexibility of the hamstring was determined by a range of passive knee extension, measured using a universal goniometer, with the subject in the supine position and the hip at 90° flexion, before and after intervention. A significant increase in knee extension was found for both intervention groups after a single stretch (SS group = 7.53°, p < 0.01 and PNF group = 11.80°, p < 0.01). Both interventions resulted in a significantly greater increase in knee extension when compared to the control group (p < 0.01). The PNF group demonstrated significantly greater gains in knee extension compared to the SS group (mean difference 4.27°, p < 0.01). It can be concluded that a therapist applied SS or PNF results in a significant increase in hamstring flexibility. A hamstring (agonist) contract PNF is more effective than an SS in a single stretching session. These findings are important to physiotherapists or trainers working in clinical and sporting environments. Where in the past therapists may have spent time conducting multiple repetitions of a PNF and an SS, a single bout of either technique may be considered just as effective. A key component of the study methodology was the exclusion of a warm-up period before stretching. Therefore, the findings of efficacy of a single PNF are of particular relevance in sporting environments and busy clinical settings where time may be limited.
The effects of PNF & static stretching on knee ROM of amputee athletes.
- H Daneshmandi, A E Atri, and A Ghasemi
Brazilian Journal of Biomotricity, Volume (5), No (4), Year (2011-12) , Pages (255-262)
The effects of PNF & static stretching on knee ROM of amputee athletes. Brazilian Journal of Biomotricity. v. 5, n. 4, p. 255-262, 2011. Flexibility is one of the most important factors in athletic preformance injuries prevantion especially in rehabilatation of athletic disabled. In order to maintain and develop ROM in an amputated limb, the superior joint of the stump should be under effective stretching exercises. Therefore the purpose of the present study was to compare the effects of two methods of static stretching and PNF (HR) on increasing the knee ROM of B.K. amputee athletes. The subjects were consisted of 19 B.K. male amputated athletes, with mean age of 35± 5years; and mean stump length of 19± 7 cm., which they were randomly divided into two groups of static stretching exercises (N=9); and PNF exercises (N=10). ROMs were measured by use of a Lighton Flexometer.The exercise protocol of both groups consisted of 12 sessions of 20 minutes. Results were concluded in both training programs of static stretching method and PNF (HR), the ROM of the knee joint increased significantly (P≤ 0.05). There was no significant difference between two methods of stretching exercises. The present study showed the effects of flexibility exercises on improvement of ROM of knee joint of B.K amputees. Therefor it emphasizes the requirements of performing static stretching exercises and PNF exercises by the coaches in order to improve physical condition of amputees and to rehabilitate them.
Active, passive and proprioceptive neuromuscular facilitation stretching are comparable in improving the knee flexion range in people with total knee replacement: a randomized controlled trial.
- TPY Chow and GYF Ng
Clin Rehabil. 2010 Oct;24(10):911-8.
Objective: To compare the immediate and medium-term effects of three stretching methods on the knee flexion range in people with a total knee replacement. Design: Randomized clinical trial. Setting: Rehabilitation hospital. Subjects: 117 patients were recruited and 100 (mean age: 68.43 ± 7.95 years) of them completed the study. Interventions: Patients receiving total knee replacement due to knee osteoarthritis were randomly assigned into 3 groups of: active stretching (group 1, n =32), passive stretching (group 2, n =35) and proprioceptive neuromuscular facilitation stretching (group 3, n =33). Main measures: The immediate change in both active and passive knee flexion range after the first treatment session and the pattern of change in these ranges throughout the 2-week study period were compared among the three groups. Results: All groups demonstrated significant improvement in knee ranges with time. The active range of group 1 improved by 19.9°, group 2 by 25.3° and group 3 by 22.5° throughout the 2-week period, whereas the improvements in the passive range were 18.8°, 24.5° and 22.7°, respectively. For between-group comparisons, no significant difference was found in both active (P = 0.647) and passive (P = 0.501) knee range immediately after stretching. For the changes at 2 weeks, there was also no significant difference among the groups in both active (P = 0.716) and passive (P = 0.959) knee ranges. Conclusion: This study revealed that all three modes of stretching were associated with an increase in the knee flexion range of patients after total knee replacement, with no statistically significant differences between the changes seen.
Flexibility Considerations: PNF Stretching.
- J Giandonato
Coaches, trainers, and athletes alike have abandoned traditional static stretches and potentially harmful ballistic stretches in exchange of PNF stretching. I know what you novices are thinking. Another freaking acronym to remember, right? Proprioceptive Neuromuscular Facilitation has been found to be useful in both clinical and athletic settings and highly effective in treating patients and improving athletic performance. Let’s delve into the mechanisms of PNF stretching, the rationale supporting its prescription and use, and the potential implications and contraindications behind it.
The efficacy of two modified proprioceptive neuromuscular facilitation stretching techniques in subjects with reduced hamstring muscle length.
- Youdas JW, Haeflinger KM, Kreun MK, Holloway AM, Kramer CM, Hollman JH.
Physiother Theory Pract. 2010 May;26(4):240-50.
Difference scores in knee extension angle and electromyographic (EMG) activity were quantified before and after modified proprioceptive neuromuscular facilitation (PNF) hold-relax (HR) and hold-relax-antagonist contraction (HR-AC) stretching procedures in 35 healthy individuals with reduced hamstring muscle length bilaterally (knee extension angle <160 degrees ). Participants were randomly assigned each PNF procedure to opposite lower extremities. Knee extension values were measured by using a goniometer. EMG data were collected for 10 seconds before and immediately after each PNF stretching technique and normalized to maximum voluntary isometric contraction (% MVIC). A significant time by stretch-type interaction was detected (F(1,34) = 21.1; p < 0.001). Angles of knee extension for HR and HR-AC were not different prior to stretching (p = 0.45). Poststretch knee extension angle was greater in the HR-AC condition than the HR condition (p < 0.007). The proportion of subjects who exceeded the minimal detectable change (MDC(95)) with the HR-AC stretch (97%) did not differ (p = 0.07) from the proportion who exceeded the MDC(95) with the HR stretch (80%). Because EMG activation increased (p < 0.013) after the HR-AC procedure, it is doubtful a relationship exists between range of motion improvement after stretching and inhibition of the hamstrings. On average the 10-second modified HR procedure produced an 11 degrees gain in knee extension angle within a single stretch session.
Effects of quadriceps and hamstrings proprioceptive neuromuscular facilitation stretching on knee movement sensation
- Streepey JW, Mock MJ, Riskowski JL, Vanwye WR, Vitvitskiy BM, Mikesky AE.
J Strength Cond Res. 2010 Apr;24(4):1037-42.
Stretching before competition has traditionally been thought to benefit performance; however, recent evidence demonstrating reduced muscle force and power immediately after stretching suggests otherwise. We hypothesized that knee joint position sense would be diminished immediately after proprioceptive neuromuscular facilitation (PNF) stretching to the hamstrings and quadriceps. Eighteen subjects (aged 18-30 years) were seated with their dominant foot attached to a motorized arm with the knee flexed at 135 degrees . To block external cues, the subjects wore a blindfold, earplugs, and headphones providing white noise. The knee was displaced in either the flexion or the extension direction at a velocity of 0.4 degrees .s, and subjects pressed a button when they sensed motion. The knee was returned to 135 degrees , and the test was repeated for a total of 10 trials. The PNF group received PNF stretching to the hamstrings and quadriceps of the dominant leg. The SHAM group had the dominant leg passively moved within each subject’s functional range of motion. The ability to detect knee movement was retested in the PNF and SHAM groups. Pre- and posttest latencies between movement onset and subject response were analyzed. Results indicated that the PNF group had significantly increased latencies after stretching (from 2.56 +/- 0.83 to 3.46 +/- 1.90 seconds) compared with the SHAM group (3.93 +/- 2.40 to 3.72 +/- 2.15 seconds). It is concluded that PNF stretching of the hamstrings and quadriceps may acutely diminish sensitivity to knee movement. For coaches and trainers, these findings are consistent with previous reports of loss in muscle force and power immediately after stretching, suggesting that stretching just before competition may diminish performance.
The use of proprioceptive neuromuscular facilitation in physiotherapy practice.
- S Westwater-Wood, N Adams
Physical Therapy Reviews, Volume 15, Number 1, February 2010 , pp. 23-28(6)
Aims: The aim of this paper is to critically review the evidence base for the use of proprioceptive neuromuscular facilitation (PNF) in physiotherapy practice. Given the evolving understanding of underlying physiological concepts and research developments in the more than 50 years since Herman Kabat originated the concept, there is a need to review the current evidence base. Method: Empirical studies investigating the effectiveness of PNF for increasing range of movement and functional rehabilitation for clinical and non-clinical populations along with patterns and irradiation concepts were reviewed. Results: Although it was difficult to draw definitive conclusions due to the lack of cognate studies and varying methodological quality of papers, a number of studies did demonstrate encouraging results for the use of PNF, particularly with regard to increasing range of movement. Conclusions: Further research is needed to explore individual components of PNF therapeutic approaches and their wider application in key clinical populations such as stroke with standardized outcome measures appropriate to clinical practice. Secondly there is need for the development of new paradigms to fully consider the underlying physiological concepts explaining the effectiveness of PNF.
Clinical massage and modified Proprioceptive Neuromuscular Facilitation stretching in males with latent myofascial trigger points.
- Athanasios Trampas, Athanasios Kitsios, Evagelos Sykaras, Stamatios Symeonidis, and Lazaros Lazarou
Phys Ther Sport, 2010 vol. 11 (3) pp. 91-98
OBJECTIVES: To determine the immediate effects of modified Proprioceptive Neuromuscular Facilitation (PNF) stretching (group I) versus Myofascial Trigger Point (MTrP) therapy plus modified PNF stretching (group II) in comparison to a control group receiving no treatment. DESIGN:Randomized, assessor-blind, (3 x 4) mixed-model repeated measures. SETTING:University laboratory. PARTICIPANTS:Thirty physically active males with tight hamstrings and at least one latent MTrP on muscles innervated by the lumbosacral, sciatic, tibial and common peroneal nerves. MAIN OUTCOME MEASURES:Knee range of motion (ROM), stretch perception, pressure pain threshold (PPT) and subjective pain intensity. Outcomes were evaluated at baseline, immediately after treatment, at 10 and 30 min. RESULTS:Significant changes over time occurred for group II in all outcomes (p < or = 0.001). Group II also showed lower pain intensity scores than group I immediately post-treatment (p = 0.045) and a strong clinical effect over group I in ROM at all follow-ups (effect sizes = 0.9-1.0, p < or = 0.05). Other differences were found between both stretching groups as compared to the control group (p < or = 0.05). CONCLUSION:The results indicate immediate pre- to post-treatment benefits from MTrP therapy combined with modified PNF stretching in young and physically active males with latent MTrPs.
The effects of the contract-relax-antagonist-contract form of proprioceptive neuromuscular facilitation stretching on postural stability.
- Edwin E Ryan, Mark D Rossi, and Richard Lopez
J Strength Cond Res, 2010 vol. 24 (7) pp. 1888-1894
To investigate the effects of the contract-relax-antagonist-contract (CRAC) form of proprioceptive neuromuscular facilitation (PNF) stretching, with and without a warm-up, on postural stability. Thirty volunteers (15 men and 15 women, age: 25.17 +/- 5.4 years, height: 173.76 +/- 8.2 cm, and weight: 72.03 +/- 14.87 kg) were randomly assigned to 1 of 3 conditions: warm-up and stretch (WS), stretching only (SO), and a control condition (CON). Contract-relax-antagonist-contract PNF of the hamstrings, plantar flexors, and hip flexors was performed during WS and SO. A 6-minute treadmill warm-up was applied before CRAC in the WS condition. Measures of anterior/posterior and medial/lateral (M/L) postural stability were taken before and after treatment conditions. A 2 x 3 analysis of variance was used to assess for differences between conditions. Significance was set at p < 0.05. There was a time x condition interaction (F = 3.962,58; p = 0.024, Power = 0.69) for M/L stability. There was a difference between WS and CON (p = 0.037, Power = 0.57) and SO and CON (p = 0.041, Power = 0.51) posttesting. This study suggests that CRAC PNF stretching with or without warm-up improves M/L stability. Contract-relax-antagonist-contract form of stretching is a useful protocol for improving M/L stability.
Optimal contraction intensity during proprioceptive neuromuscular facilitation for maximal increase of range of motion.
- Peter W Sheard and Tim J Paine
J Strength Cond Res, 2010 vol. 24 (2) pp. 416-421
An informal review of literature on the use of postisometric relaxation (PIR) type proprioceptive neuromuscular facilitation (PNF) indicates that the force of contraction requested from the athlete ranges from 10 to 100% of maximum voluntary isometric contraction (MVIC). The purpose of this study was therefore to determine if an optimal contraction intensity to elicit maximum positive change in range of motion (DeltaROM) exists. This research question was tested across a convenience sample of 56 (37 male and 19 female) university athletes. Target contractions during PNF interventions were set at 20, 50, and 100% MVIC. Pre- and post-PNF intervention hip flexion range of motion (ROM) was measured on a unilateral straight leg raise. The target MVIC of 20, 50, and 100% elicited mean pre-post intervention DeltaROM of 8.4, 12.9, and 11.6 degrees , respectively (all p < or = 0.0001). Differences in pre-post intervention DeltaROM between target contraction intensities were also significant (p = 0.016 to < or = 0.0001). A peak DeltaROM of 13.3 degrees was found at a PNF contraction intensity of 64.3% MVIC. Where optimizing increased ROM in healthy athletes is the desired outcome of PIR-PNF application, coaches and trainers should elicit contraction intensities of approximately 65% MVIC.
Proprioceptive neuromuscular facilitation: time for a paradigm shift?.
- Sheard, P
Physical Therapy Reviews, Volume 15, Number 2, April 2010 , pp. 117-118(2)
Athlete compliance to therapist requested contraction intensity during proprioceptive neuromuscular facilitation.
- Peter W Sheard, Paul M Smith, Tim J Paine
Man Ther, 2009 vol. 14 (5) pp. 539-543
Contraction intensities between 10 and 100% maximal voluntary contraction (MVC) have been proposed in varying muscle energy technique (MET) and proprioceptive neuromuscular facilitation (PNF) post-isometric relaxation (PIR) protocols. The current study was undertaken to determine if athletes were able to comply with differing therapist requested contraction intensities during (PNF) stretching protocols. Thirty-six university athletes were recruited and MVC was established at hip extension, hip adduction, and horizontal shoulder adduction. Target PIR contractions were set at 20, 50 and 100% MVC and monitored throughout the contractions with a strain gauge dynamometer. Athletes were not able to match the target contraction values at 20 and 100% MVC (P< or =0.001). When examined for consistency across the three component contractions within each of the three PIR protocols, the athletes demonstrated widely variable scores (coefficient of variation (CV)=23.2-36.4% at 20% MVC; CV=19.3-29.4% at 50% MVC; and, CV=9.4-14.5% at 100% MVC). Our findings indicate that this group of athletes displayed a poor level of compliance to varying therapist requested contraction intensities with respect to both accuracy and consistency.
The Effects of Indirect Treatment of Proprioceptive Neurosmuscular Facilitation.
- H Sato and H Maruyama
Journal of Physical Therapy Science Vol. 21 (2009) No. 2 P 189-193
The purpose of this research was to clarify the effects of indirect treatment of proprioceptive neuromuscular facilitation (PNF). [Subjects] The subjects were thirty healthy male volunteers. Their mean age was 21.1 ± 1.1 years. [Methods] This study examined the extension force of the contralateral lower limb when manual isometric resistance exercise was performed by an upper limb at the start, middle, and final positions of PNF and shoulder flexion. A hand-held dynamometer measured the extension force of the contralateral lower limb. [Results] The extension force of the contralateral lower limb increased when an isometric resistance exercise was performed by an upper limb at the final position of the flexion-abduction-external rotation pattern of PNF. [Discussion] The extension force of the contralateral lower limb increased more with PNF movement than in shoulder flexion of an upper limb. The result suggests that isometric resistance exercise by an upper limb at the final position of PNF emphasized the „continue movement” and the systemic balance reaction occurred toward the side of the contralateral lower limb. This finding, therefore, could be applied to the treatment of patients having difficulty with moving their own lower limbs.
PNF-based rehabilitation in patients with severe haemophilic arthropathy-case study.
- M Luterek, M Baranowski, and W Zakiewicz
Ortop Traumatol Rehabil. 2009 May-Jun;11(3):280-9.
Haemophilia is a congenital haemorrhagic diathesis that in its most severe form leads to a seriously disabling arthropathy as a result of recurring intraarticular bleeding. Within the last couple of years there have been significant advances in the treatment of haemophiliacs that are helping to prevent crippling musculoskeletal deformities, but a relatively large number of young adults still present with advanced arthropathic changes when treatment was started too late or has failed to prevent changes from taking place. We present the case of a 44-year-old male with advanced haemophilic arthropathy of the knee and ankle joints, who, during 8 weeks of therapy that consisted of physical therapy and rehabilitation using PNF techniques (Proprioceptive Neuromuscular Facilitation), achieved mobility improvement according to the SPPB scale (Short Physical Performance Battery Test) and a reduction of pain in the knee and ankle joints, according to a VAS scale. The therapeutic regimen proved to be an effective method improving the locomotor function of the patient.
The effect of a four-week proprioceptive neuromuscular facilitation stretching program on isokinetic torque production.
- F Higgs and S L Winter
J Strength Cond Res 2009 Aug;23(5):1442-7
Flexibility is widely accepted as an important component of fitness, yet flexibility training can be detrimental to muscle performance particularly where a high number of stretch cycles are performed. The purpose of this study was to investigate whether chronic proprioceptive neuromuscular facilitation (PNF) stretch training could successfully improve the knee flexion range of motion without having a detrimental effect on the peak isokinetic torque of the quadriceps. The minimum knee angle in flexion and the peak isokinetic quadriceps torque were measured at 120 and 270 degrees xs. Subjects then participated in a 4-week quadriceps flexibility training program consisting of 3 cycles of PNF stretching performed 3 times a week. The range of motion was recorded before and after the first stretching session of each week. At the end of the 4-week period, the peak isokinetic quadriceps torque and flexibility were again measured. The mean (SE) improvement in the knee flexion range of motion over the whole program was 9.2 degrees (1.45 degrees ), and typical gains after a single stretching session were around 3 degrees . Post hoc analysis showed that the pretraining session range of motion was significantly improved in week 4 compared with the pretraining session range of motion in weeks 1 and 2 (p < 0.05). There was no change (p = 0.9635) in the peak isokinetic torque produced at 120 degrees xs (week 1: 121.9 (4.6) N x m; week 2: 121.9 (5.2) N x m) or at 270 degrees xs (week 1: 88.1 (3.4) N x m; week 2: 88.6 (4.9) N x m). These findings suggest that it is possible to improve flexibility using 3 PNF stretch cycles performed 3 times a week without altering muscle isokinetic strength characteristics.
Effect of proprioceptive neuromuscular facilitation stretching on the plantar flexor muscle-tendon tissue properties.
- N N Mahieu, A Cools, B De Wilde, M Boon, and E Witvrouw
Scand J Med Sci Sports, 2009 vol. 19 (4) pp. 553-560
Proprioceptive neuromuscular facilitation (PNF) stretching programs have been shown to be the most effective stretching technique to increase the range of motion (ROM). The objective of this study was to examine the mechanism of effect of PNF stretching on changes in the ROM. Sixty-two healthy subjects were randomized into two groups: a PNF stretching group and a control group. The PNF group performed a 6-week stretching program for the calf muscles. Before and after this period, all subjects were evaluated for dorsiflexion ROM, passive resistive torque (PRT) of the plantar flexors and stiffness of the Achilles tendon. The results of the study revealed that the dorsiflexion ROM was significantly increased in the PNF group (DeltaROMext: 5.97+/-0.671 degrees ; DeltaROMflex: 5.697+/-0.788 degrees ). The PRT of the plantar flexors and the stiffness of the Achilles tendon did not change significantly after 6 weeks of PNF stretching. These findings provide evidence that PNF stretching results in an increased ankle dorsiflexion. However, this increase in ROM could not be explained by a decrease of the PRT or by a change in stiffness of the Achilles tendon, and therefore can be explained by an increase in stretch tolerance.
Neurophysiological reflex mechanisms’ lack of contribution to the success of PNF stretches.
- Ulrike H Mitchell, J William Myrer, J Ty Hopkins, Iain Hunter, J Brent Feland, and Sterling C Hilton
J Sport Rehabil, 2009 vol. 18 (3) pp. 343-357
BACKGROUND AND PURPOSE:Proprioceptive neuromuscular facilitation (PNF) stretches are widely used in athletics and rehabilitation. Although it has been shown that they produce better range-of-motion (ROM) increases than the slow or static stretch, the mechanisms responsible remain an enigma. This study was conducted to determine whether the previously proposed neurophysiological mechanisms of reciprocal inhibition and autogenic inhibition are responsible for the success of PNF stretches. In addition, the authors assessed the existence of the phenomenon of successive induction because it is used to strengthen reciprocal inhibition. METHODS:Eighteen subjects 17-44 y performed the PNF stretches contract-relax (CR) and contract-relax, agonist contract (CRAC). EMG data were collected from the medial hamstring muscles via surface and indwelling wire electrodes and analyzed for reciprocal inhibition and successive induction, as well as autogenic inhibition (surface electrodes only). RESULTS:Reciprocal inhibition was not evident. The results indicated an elevated rather than an inhibited EMG during the antagonist contraction, possibly representing cocontraction. The authors did confirm the presence of successive induction. Autogenic inhibition was also not evident, and the expected inhibition and therefore lower EMG values after muscle contraction were not observed; instead, they were higher than baseline. CONCLUSION:Previous neurophysiological explanations for mechanisms of PNF stretching appear to be inadequate. This study corroborates previous findings that a muscle’s tone increases during its antagonist’s contraction. Other explanations should be considered regarding the mechanism for the effectiveness of the CRAC and CR PNF techniques in a nonneurologically impaired population.
An examination of the stretching practices of Division I and Division III college football programs in the midwestern United States.
- Lawrence W Judge, Bruce Craig, Steve Baudendistal, Kimberly J Bodey
J Strength Cond Res, 2009 vol. 23 (4) pp. 1091-1096
Research supports the use of preactivity warm-up and stretching, and the purpose of this study was to determine whether college football programs follow these guidelines. Questionnaires designed to gather demographic, professional, and educational information, as well as specific pre- and postactivity practices, were distributed via e-mail to midwestern collegiate programs from NCAA Division I and III conferences. Twenty-three male coaches (12 from Division IA schools and 11 from Division III schools) participated in the study. Division I schools employed certified strength coaches (CSCS; 100%), whereas Division III schools used mainly strength coordinators (73%), with only 25% CSCS. All programs used preactivity warm-up, with the majority employing 2-5 minutes of sport-specific jogging/running drills. Pre stretching (5-10 minutes) was performed in 19 programs (91%), with 2 (9%) performing no pre stretching. Thirteen respondents used a combination of static/proprioceptive neuromuscular facilitation/ballistic and dynamic flexibility, 5 used only dynamic flexibility, and 1 used only static stretching. All 12 Division I coaches used stretching, whereas only 9 of the 11 Division III coaches did (p = 0.22). The results indicate that younger coaches did not use pre stretching (p = 0.30). The majority of the coaches indicated that they did use post stretching, with 11 of the 12 Division I coaches using stretching, whereas only 5 of the 11 Division III coaches used stretching postactivity (p = 0.027). Divisional results show that the majority of Division I coaches use static-style stretching (p = 0.049). The results of this study indicate that divisional status, age, and certification may influence how well research guidelines are followed. Further research is needed to delineate how these factors affect coaching decisions.
The effect of proprioceptive neuromuscular facilitation and static stretch training on running mechanics.
- Nicholas Caplan, Rebecca Rogers, Michael K Parr, and Philip R Hayes
J Strength Cond Res, 2009 vol. 23 (4) pp. 1175-1180
There is a long-standing belief that increased range of movement (RoM) at the hip or knee will improve running mechanics; however, few studies have examined the effect of such an increase in RoM. The aim of this study was to determine the influence of 2 methods of stretch training (static and proprioceptive neuromuscular facilitation [PNF]) on high-velocity running. Eighteen rugby league players were assessed for maximum sprinting velocity. They were randomly allocated into 2 stretch training groups: PNF or static. Each group trained their hamstrings 4 d x w(-1) for 5 weeks. Pre- and posttraining subjects were videoed while running at 80% of maximum velocity. The video was digitized to identify biomechanical changes in hip flexion (HF), knee extension (KE), stride length (SL), stride rate (SR), and contact time (tc). Stretch training resulted in gains (p < 0.05) in HF for the static stretch (SS) (4.9%) and PNF (7.6%) groups. There were reductions in KE (p < 0.05) for SS (1.0%) and PNF (1.6%) groups. Stride mechanics were also altered after training. There were increases in SL (p < 0.05) for SS (7.1%) and PNF (9.1%) and a concomitant reduction in SR (p < 0.05) for SS (1.9%) and PNF (4.3%). No changes were observed in tc in either group. In conclusion, both SS and PNF training improved HF RoM and running mechanics during high-velocity running. These findings suggest that stretch training undertaken at the end of regular training is effective in changing running mechanics.
Effects of different stretching techniques on the outcomes of isokinetic exercise in patients with knee osteoarthritis.
- Ming-Cheng Weng, Chia-Ling Lee, Chia-Hsin Chen, Jui-Jen Hsu, Wei-Der Lee, Mao-Hsiung Huang, and Tien-Wen Chen
Kaohsiung J Med Sci, 2009 vol. 25 (6) pp. 306-315
We recruited 132 subjects with bilateral knee osteoarthritis (Altman Grade II) to compare the effects of different stretching techniques on the outcomes of isokinetic muscle strengthening exercises. Patients were randomly divided into four groups (I-IV). The patients in Group I received isokinetic muscular strengthening exercises, Group II received bilateral knee static stretching and isokinetic exercises, Group III received proprioceptive neuromuscular facilitation (PNF) stretching and isokinetic exercises, and Group IV acted as controls. Outcomes were measured by changes in Lequesne’s index, range of knee motion, visual analog pain scale, and peak muscle torques during knee flexion and extension. Patients in all the treated groups experienced significant reductions in knee pain and disability, and increased peak muscle torques after treatment and at follow-up. However, only patients in Groups II and III had significant improvements in range of motion and muscle strength gain during 60 degrees/second angular velocity peak torques. Group III demonstrated the greatest increase in muscle strength gain during 180 degrees/second angular velocity peak torques. In conclusion, stretching therapy could increase the effectiveness of isokinetic exercise in terms of functional improvement in patients with knee osteoarthritis. PNF techniques were more effective than static stretching.
A randomized controlled trial of hamstring stretching: comparison of four techniques.
- Jo M Fasen, Annie M O’Connor, Susan L Schwartz, John O Watson, Chris T Plastaras, Cynthia W Garvan, Creso Bulcao, Stephen C Johnson, and Venu Akuthota
J Strength Cond Res, 2009 vol. 23 (2) pp. 660-667
This study compared the efficacy of 4 different hamstring-stretching techniques. Flexibility can be achieved by a variety of stretching techniques, yet little research has been performed on the most effective method. The 2 basic types include active stretching, in which range of motion is increased through voluntary contraction, and passive stretching, in which range of motion is increased through external assistance. The 2 types of active stretching include neuromobilization and proprioceptive neuromuscular facilitation (PNF). Our study aims to determine which type of stretching technique is most effective in improving hamstring length. One hundred subjects between the ages of 21 and 57 were enrolled in the study. Intrarater reliability of hamstring length measurement was performed using 10 subjects. All 100 subjects were included in a randomized controlled trial of 5 different groups comparing different hamstring-stretching techniques. Outcome measures, including hamstring length and perceived level of hamstring tightness, were recorded on all subjects initially, at 4 weeks, and at 8 weeks. After 4 weeks of stretching, there was a statistically significant improvement in hamstring length (p < 0.05) using active stretches as compared with passive stretches. From weeks 4 through 8, hamstring length for the active stretching groups decreased. After 8 weeks of stretching, the straight leg raise (SLR) passive stretch group had the greatest improvement in hamstring length. There was no correlation between hamstring flexibility and age, initial tightness, or frequency of exercise per week. Improvement in hamstring flexibility was greatest for the SLR passive stretch. Also, using PNF in the 90/90 active stretch provided better knee range-of-motion improvements than the 90/90 passive methods did.
Investigation into the long-term effects of static and PNF stretching exercises on range of motion and jump performance.
- B Yuktasir, F Kaya
J Bodyw Mov Ther. 2009 Jan;13(1):11-21.
The purpose of the present study was to investigate the long-term effects of two different stretching techniques on the range of motion (ROM) and on drop jump (DJ). DJ scores were assessed by means of a contact mat connected to a digital timer. ROM was measured by use of a goniometer. The training was carried out four times a week for 6 weeks on 10 subjects as passive static stretching (SS), and on 9 subjects as contract-relax PNF (CRPNF) stretching. The remaining nine subjects did not perform any exercises (control group). One-way Analysis of Variance (ANOVA) results indicated that the differences among groups on DJ were not statistically different (F(2,27)=.41, p>.05). ROM values were significantly higher for both stretching groups, while no change was observed for the control group. In conclusion, static and proprioceptive neuromuscular facilitation (PNF) stretching techniques improved the ROM, but neither of the stretching exercises had any statistically significant effect on the DJ scores
The effects of proprioceptive neuromuscular facilitation and dynamic stretching techniques on vertical jump performance.
- B K Christensen and B J Nordstrom
J Strength Cond Res. 2008 Nov;22(6):1826-31.
The purpose of this study was to investigate the effects of 3 different warm-ups on vertical jump performance. The warm-ups included a 600-m jog, a 600-m jog followed by a dynamic stretching routine, and a 600-m jog followed by a proprioceptive neuromuscular facilitation (PNF) routine. A second purpose was to determine whether the effects of the warm-ups on vertical jump performance varied by gender. Sixty-eight men and women NCAA Division I athletes from North Dakota State University performed 3 vertical jumps on a Just Jump pad after each of the 3 warm-up routines. The subjects were split into 6 groups and rotated between 3 warm-up routines, completing 1 routine each day in a random order. The results of the 1-way repeated measures analysis of variance showed no significant differences in the combined (p = 0.927), men’s (p = 0.798), or women’s (p = 0.978) results. The results of this study showed that 3 different warm-ups did not have a significant affect on vertical jumping. The results also showed there were no gender differences between the 3 different warm-ups.
Acute effects of static, dynamic, and proprioceptive neuromuscular facilitation stretching on muscle power in women.
- M E Manoel, M O Harris-Love, and J V Danoff
J Strength Cond Res. 2008 Sep;22(5):1528-34.
The purpose of this study was to investigate the acute effects of 3 types of stretching-static, dynamic, and proprioceptive neuromuscular facilitation (PNF)-on peak muscle power output in women. Concentric knee extension power was measured isokinetically at 60 degrees x s(-1) and 180 degrees x s(-1) in 12 healthy and recreationally active women (mean age +/- SD, 24 +/- 3.3 years). Testing occurred before and after each of 3 different stretching protocols and a control condition in which no stretching was performed. During 4 separate laboratory visits, each subject performed 5 minutes of stationary cycling at 50 W before performing the control condition, static stretching protocol, dynamic stretching protocol, or PNF protocol. Three submaximal warm-up trials preceded 3 maximal knee extensions at each testing velocity. A 2-minute rest was allowed between testing at each velocity. The results of the statistical analysis indicated that none of the stretching protocols caused a decrease in knee extension power. Dynamic stretching produced percentage increases (8.9% at 60 degrees x s(-1) and 6.3% at 180 degrees x s(-1)) in peak knee extension power at both testing velocities that were greater than changes in power after static and PNF stretching. The findings suggest that dynamic stretching may increase acute muscular power to a greater degree than static and PNF stretching. These findings may have important implications for athletes who participate in events that rely on a high level of muscular power.
PNF induced irradiation on the contralateral lower extremity with EMG measuring.
- E Németh and V Steinhausz
Proceedings of the 3rd Hungarian Conference on Biomechanics, Budapest, July 4-5, 2008
The aim of the study was to investigate how the cross-training effect to reach higher effectiveness in PNF (Proprioceptive neuromuscular facilitation) treatment can be increased. PNF techniques apply three-dimensional movement, stretch reflex, resistance to promote functional movement.  We looked for the answer to the following: how much does the abduction (straddle)positioning of the examined limb and hip flexion of contralateral limb influence the extent of irradiation during an isometric contraction. Irradiation is a spreading and increased strength of a muscle response.  Flexion PNF pattern was applied on lower extremity to facilitate the muscles on the opposite side. This investigation is based upon a single electromyographic measurement. The electrical potential of the examined hip and knee muscles were detected with eight channel Zebris Bluetooth EMG equipment (Electromyograph) on the dominant lower extremity. 20 healthy physiotherapist students did the exercises in determined settings. Our research show that the grade of irradiation is connection with the placing of the contralateral limb. The abduction setting of the unmoved limb and the hip flexion on the moved limb has a significant effect on irradiation. A hip abduction of a lesser degree and a hip flexion of a higher degree induced significantly stronger contralateral muscle activity.
The effects of PNF training on the facial profile.
- M Namura, M Motoyoshi, Y Namura, and N Shimizu
J Oral Sci. 2008 Mar;50(1):45-51.
Although orthodontic treatment improves dentoalveolar problems, the facial profile seldom changes because the perioral muscles do not easily adapt to the new morphological circumstances. We employed proprioceptive neuromuscular facilitation (PNF), which is training with added resisted movement to motions such as lifting the upper lip, lowering the lower lip, and sticking out the tongue, to adapt the perioral muscles to the new morphological circumstances. The subjects were 40 adults with an average age of 29.6 years. A series of PNF exercises was performed three times per day for 1 month. Lateral facial photographs were taken using a digital camera before training (T(0)), after training (T(1)), and 1 month after the end of training (T(2)). The nasolabial (NL), mentolabial (ML), and mentocervical (MC) angles were measured, and linear measurements were taken to verify the change of each measurement point. In the test group, the NL and ML angles significantly increased (P < 0.05), and the MC angle significantly decreased after the PNF exercise. From T(1) to T(2), the NL and ML angles decreased significantly, while the MC angle increased significantly. No significant differences were observed in these angles when the values measured at T(0) and T(2) were compared. Although the training appeared to be effective for sharpening the mouth and submandibular region, continued training is necessary to avoid relapse.
Acute effects of different stretching exercises on muscular endurance.
- Bruno L Franco, Gabriel R Signorelli, Gabriel S Trajano, and Carlos G de Oliveira
J Strength Cond Res, 2008 vol. 22 (6) pp. 1832-1837
This study aims to evaluate the acute effects of different stretching exercises on muscular endurance in men, in terms of the number of sets, set duration, and type of stretching. Two experiments were conducted; in the first one (E1), the subjects (n = 19) were evaluated to test the effect on the number of sets, and, in the second one (E2), the subjects (n = 15) were tested for the effect of set duration and type of stretching. After a warm-up of 10-15 repetitions of a bench press (BP) with submaximal effort, a one-repetition maximum (1RM) test was applied. For E1, BP endurance was evaluated after static stretching comprising one set of 20 seconds (1 x 20), two sets of 20 seconds (2 x 20), and three sets of 20 seconds (3 x 20). For E2, BP endurance was evaluated after static stretching comprising one set of 20 seconds (1 x 20), one set of 40 seconds (1 x 40), and proprioceptive neuromuscular facilitation (PNF) stretching. All tests were performed 48-72 hours apart, at which time the muscular endurance was assessed through the maximal number of repetitions (NR) of BP at 85% of 1RM until fatigue. The NR and the overload volume (OV) were compared among tests through repeated-measures analysis of variance. No significant effect of the number of sets on muscular endurance was observed because no statistically significant difference was found when comparing all stretching exercises of E1 in terms of NS (p = 0.5377) and OV (p = 0.5723). However, significant reductions were obtained in the set duration and PNF on NR (p < 0.0001) and OV (p < 0.0001), as observed in E2. The results suggest that a stretching protocol can influence BP endurance, whereas a decrease in endurance is suggested to be attributable to set duration and PNF. On the other hand, a low volume of static stretching does not seem to have a significant effect on muscular endurance.
The acute effects of dynamic and ballistic stretching on vertical jump height, force, and power.
- Jason R Jaggers, Ann M Swank, Karen L Frost, and Chong D Lee
J Strength Cond Res, 2008 vol. 22 (6) pp. 1844-1849
Stretching before performance is a common practice among athletes in hopes of increasing performance and reducing the risk of injury. However, cumulative results indicate a negative impact of static stretching and proprioceptive neuromuscular facilitation (PNF) on performance; thus, there is a need for evaluating other stretching strategies for effective warm-up. The purpose of this study was to compare the differences between two sets of ballistic stretching and two sets of a dynamic stretching routine on vertical jump performance. Twenty healthy male and female college students between the ages of 22 and 34 (24.8 +/- 3 years) volunteered to participate in this study. All subjects completed three individual testing sessions on three nonconsecutive days. On each day, the subjects completed one of three treatments (no stretch, ballistic stretch, and dynamic stretch). Intraclass reliability was determined using the data obtained from each subject. A paired samples t-test revealed no significant difference in jump height, force, or power when comparing no stretch with ballistic stretch. A significant difference was found on jump power when comparing no stretch with dynamic stretch, but no significant difference was found for jump height or force. Statistics showed a very high reliability when measuring jump height, force, and power using the Kistler Quattro Jump force plate. It seems that neither dynamic stretching nor ballistic stretching will result in an increase in vertical jump height or force. However, dynamic stretching elicited gains in jump power poststretch.
Electromyographic activity of the masticatory and cervical muscles during resisted jaw opening movement.
- Armijo-Olivo S, Magee DJ.
J Oral Rehabil. 2007 Mar;34(3):184-94.
One of the relaxation techniques that have been used by physical therapists when treating patients with temporomandibular disorders, is the agonist contract-antagonist relax technique (AC). When the AC technique is applied, a submaximal resistance to the jaw opening movement is necessary to cause relaxation of the masticatory muscles. No information about the effect of this technique on masticatory or cervical muscles has been found in the literature. Thus, the aim of this study was to evaluate the electromyographic activity of the masseter and anterior temporalis and the upper trapezius and splenius capitis during resisted jaw opening movement. A convenience sample of 30 students was used. Electromyography activity of the superficial masseter, anterior temporalis, upper trapezius and splenius capitis was registered before, during and after the application of this resistive movement to jaw opening. A two-way anova with repeated measures analysis was used to analyse data. The level of significance was at alpha = 0.05. The EMG activity of both the masticatory muscles and the cervical muscles increased during and after the application of resisted jaw opening (P < 0.05). Based on the results obtained from this study, the behaviour of all muscles analysed (masseter, anterior temporalis, splenius capitis and upper trapezius) was similar. All muscles increased their activity when the resistance to the jaw opening movement was applied. Complex muscular interactions of the supra- and infrahyoid muscles (jaw openers), masticatory muscles, and cervical muscles may exist to stabilize the craniomandibular system during resisted jaw opening.
Effects of proprioceptive neuromuscular facilitation stretching on stiffness and force-producing characteristics of the ankle in active women.
- Sven S Rees, Aron J Murphy, Mark L Watsford, Ken A McLachlan, and Aaron J Coutts
J Strength Cond Res, 2007 vol. 21 (2) pp. 572-577
The purpose of this study was to examine the effect of proprioceptive neuromuscular facilitation (PNF) stretching on musculotendinous unit (MTU) stiffness of the ankle joint. Twenty active women were assessed for maximal ankle range of motion, maximal strength of planter flexors, rate of force development, and ankle MTU stiffness. Subjects were randomly allocated into an experimental (n = 10) group or control group (n = 10). The experimental group performed PNF stretching on the ankle joint 3 times per week for 4 weeks, with physiological testing performed before and after the training period. After training, the experimental group significantly increased ankle range of motion (7.8%), maximal isometric strength (26%), rate of force development (25%), and MTU stiffness (8.4%) (p < 0.001). Four weeks of PNF stretching contributed to an increase in MTU stiffness, which occurred concurrently with gains to ankle joint range of motion. The results confirm that MTU stiffness and joint range of motion measurements appear to be separate entities. The increased MTU stiffness after the training period is explained by adaptations to maximal isometric muscle contractions, which were a component of PNF stretching. Because a stiffer MTU system is linked with an improved the ability to store and release elastic energy, PNF stretching would benefit certain athletic performance due to a reduced contraction time or greater mechanical efficiency. The results of this study suggest PNF stretching is a useful modality at increasing a joint’s range of motion and its strength.
The effect of static, ballistic, and proprioceptive neuromuscular facilitation stretching on vertical jump performance.
- Paul S Bradley, Peter D Olsen, and Matthew D Portas
J Strength Cond Res, 2007 vol. 21 (1) pp. 223-226
The purpose of this study was to compare the acute effects of different modes of stretching on vertical jump performance. Eighteen male university students (age, 24.3 +/- 3.2 years; height, 181.5 +/- 11.4 cm; body mass, 78.1 +/- 6.4 kg; mean +/- SD) completed 4 different conditions in a randomized order, on different days, interspersed by a minimum of 72 hours of rest. Each session consisted of a standard 5-minute cycle warm-up, accompanied by one of the subsequent conditions: (a) control, (b) 10-minute static stretching, (c) 10-minute ballistic stretching, or (d) 10-minute proprioceptive neuromuscular facilitation (PNF) stretching. The subjects performed 3 trials of static and countermovement jumps prior to stretching and poststretching at 5, 15, 30, 45, and 60 minutes. Vertical jump height decreased after static and PNF stretching (4.0% and 5.1%, p < 0.05) and there was a smaller decrease after ballistic stretching (2.7%, p > 0.05). However, jumping performance had fully recovered 15 minutes after all stretching conditions. In conclusion, vertical jump performance is diminished for 15 minutes if performed after static or PNF stretching, whereas ballistic stretching has little effect on jumping performance. Consequently, PNF or static stretching should not be performed immediately prior to an explosive athletic movement.
Cross-training effects of a proprioceptive neuromuscular facilitation exercise programme on knee musculature.
- N D Kofotolis and E Kellis
Physical Therapy in Sport, Volume 8, Issue 3, August 2007, Pages 109–116
Objectives To examine the cross-training effects of a proprioceptive neuromuscular facilitation training (PNF) program on peak torque and endurance. Design Factorial design. Participants Twenty-three males were assigned to a PNF group (n=12) or a control group (n=11). Interventions The PNF program included training of the knee extensor and flexor muscles for a period of 8 weeks, exercising three times a week. PNF training included performance of knee movements through range of motion against manual resistance. Main outcome measures Isokinetic torque and fatigue of the knee flexors and extensors at 60, 180 and 300° s−1 were assessed prior to and immediately after the training period. Results Analysis of variance designs indicated that the PNF group demonstrated significant gains (9.9%) in knee extension torque of the contralateral leg. In contrast, no cross-training effects on peak flexion torque was observed. Conclusions Cross-training effects after PNF exercise were restricted to the knee extensor muscles. Such effects may be important when the aim of a rehabilitation program is to improve the knee extensor muscle function of an immobilized contralateral leg.
Effects of two 4-week proprioceptive neuromuscular facilitation programs on muscle endurance, flexibility, and functional performance in women with chronic low back pain.
- Nick Kofotolis and Eleftherios Kellis
Phys Ther, 2006 vol. 86 (7) pp. 1001-1012
BACKGROUND AND PURPOSE:Improving functional performance in patients with chronic low back pain is of primary importance. The purpose of this study was to examine the effects of 2 proprioceptive neuromuscular facilitation (PNF) programs on trunk muscle endurance, flexibility, and functional performance in subjects with chronic low back pain (CLBP). SUBJECTS:Eighty-six women (40.2+/-11.9 [mean+/-SD] years of age) who had complaints of CLBP were randomly assigned to 3 groups: rhythmic stabilization training, combination of isotonic exercises, and control. METHODS:Subjects trained with each program for 4 weeks with the aim of improving trunk stability and strength. Static and dynamic trunk muscle endurance and lumbar mobility were measured before, at the end of, and 4 and 8 weeks after training. Disability and back pain intensity also were measured with the Oswestry Index. RESULTS:Multivariate analysis of variance indicated that both training groups demonstrated significant improvements in lumbar mobility (8.6%-24.1%), static and dynamic muscle endurance (23.6%-81%), and Oswestry Index (29.3%-31.8%) measurements. DISCUSSION AND CONCLUSION:Static and dynamic PNF programs may be appropriate for improving short-term trunk muscle endurance and trunk mobility in people with CLBP.
Electromyographic assessment of the activity of the masticatory using the agonist contract-antagonist relax technique (AC) and contract-relax technique (CR).
- Susan Armijo Olivo and David J Magee
Man Ther, 2006 vol. 11 (2) pp. 136-145
Proprioceptive neuromuscular facilitation (PNF) techniques are a group of therapeutic procedures that may be used to cause relaxation of muscles. Studies have found controversial results when applying these techniques. The aim of the present study was to evaluate the effectiveness of masticatory muscle relaxation through the use of the contract-relax technique (CR) when compared with the agonist contract-antagonist relax technique (AC). A convenience sample of 30 students was recruited for this study. The CR and the AC techniques were applied to the subjects in order to cause relaxation of the masticatory muscles. Electromyography activity of all muscles was registered. Two way ANOVA with repeated measures analysis demonstrated that both the AC technique and the CR technique did not decrease the EMG activity of masticatory muscles (P>0.05). Instead, both techniques caused an increase in electromyographic activity of the masticatory muscles. Based on the results obtained from this study, both the CR and the AC techniques were not effective in causing relaxation of the masticatory muscles. The purported physiological mechanisms of PNF techniques, which stated that they act through reciprocal inhibition and autogenic inhibition causing muscular relaxation, are not supported by this study.
Neural adaptations to resistive exercise: mechanisms and recommendations for training practices.
- David A Gabriel, Gary Kamen, and Gail Frost
Sports Med, 2006 vol. 36 (2) pp. 133-149
It is generally accepted that neural factors play an important role in muscle strength gains. This article reviews the neural adaptations in strength, with the goal of laying the foundations for practical applications in sports medicine and rehabilitation. An increase in muscular strength without noticeable hypertrophy is the first line of evidence for neural involvement in acquisition of muscular strength. The use of surface electromyographic (SEMG) techniques reveal that strength gains in the early phase of a training regimen are associated with an increase in the amplitude of SEMG activity. This has been interpreted as an increase in neural drive, which denotes the magnitude of efferent neural output from the CNS to active muscle fibres. However, SEMG activity is a global measure of muscle activity. Underlying alterations in SEMG activity are changes in motor unit firing patterns as measured by indwelling (wire or needle) electrodes. Some studies have reported a transient increase in motor unit firing rate. Training-related increases in the rate of tension development have also been linked with an increased probability of doublet firing in individual motor units. A doublet is a very short interspike interval in a motor unit train, and usually occurs at the onset of a muscular contraction. Motor unit synchronisation is another possible mechanism for increases in muscle strength, but has yet to be definitely demonstrated. There are several lines of evidence for central control of training-related adaptation to resistive exercise. Mental practice using imagined contractions has been shown to increase the excitability of the cortical areas involved in movement and motion planning. However, training using imagined contractions is unlikely to be as effective as physical training, and it may be more applicable to rehabilitation. Retention of strength gains after dissipation of physiological effects demonstrates a strong practice effect. Bilateral contractions are associated with lower SEMG and strength compared with unilateral contractions of the same muscle group. SEMG magnitude is lower for eccentric contractions than for concentric contractions. However, resistive training can reverse these trends. The last line of evidence presented involves the notion that unilateral resistive exercise of a specific limb will also result in training effects in the unexercised contralateral limb (cross-transfer or cross-education). Peripheral involvement in training-related strength increases is much more uncertain. Changes in the sensory receptors (i.e. Golgi tendon organs) may lead to disinhibition and an increased expression of muscular force. Agonist muscle activity results in limb movement in the desired direction, while antagonist activity opposes that motion. Both decreases and increases in co-activation of the antagonist have been demonstrated. A reduction in antagonist co-activation would allow increased expression of agonist muscle force, while an increase in antagonist co-activation is important for maintaining the integrity of the joint. Thus far, it is not clear what the CNS will optimise: force production or joint integrity. The following recommendations are made by the authors based on the existing literature. Motor learning theory and imagined contractions should be incorporated into strength-training practice. Static contractions at greater muscle lengths will transfer across more joint angles. Submaximal eccentric contractions should be used when there are issues of muscle pain, detraining or limb immobilisation. The reversal of antagonists (antagonist-to-agonist) proprioceptive neuromuscular facilitation contraction pattern would be useful to increase the rate of tension development in older adults, thus serving as an important prophylactic in preventing falls. When evaluating the neural changes induced by strength training using EMG recording, antagonist EMG activity should always be measured and evaluated.
Proprioceptive neuromuscular facilitation stretching: mechanisms and clinical implications.
- M J Sharman, A G Cresswell, and S Riek
Sports Med. 2006;36(11):929-39.
Proprioceptive neuromuscular facilitation (PNF) stretching techniques are commonly used in the athletic and clinical environments to enhance both active and passive range of motion (ROM) with a view to optimising motor performance and rehabilitation. PNF stretching is positioned in the literature as the most effective stretching technique when the aim is to increase ROM, particularly in respect to short-term changes in ROM. With due consideration of the heterogeneity across the applied PNF stretching research, a summary of the findings suggests that an 'active’ PNF stretching technique achieves the greatest gains in ROM, e.g. utilising a shortening contraction of the opposing muscle to place the target muscle on stretch, followed by a static contraction of the target muscle. The inclusion of a shortening contraction of the opposing muscle appears to have the greatest impact on enhancing ROM. When including a static contraction of the target muscle, this needs to be held for approximately 3 seconds at no more than 20% of a maximum voluntary contraction. The greatest changes in ROM generally occur after the first repetition and in order to achieve more lasting changes in ROM, PNF stretching needs to be performed once or twice per week. The superior changes in ROM that PNF stretching often produces compared with other stretching techniques has traditionally been attributed to autogenic and/or reciprocal inhibition, although the literature does not support this hypothesis. Instead, and in the absence of a biomechanical explanation, the contemporary view proposes that PNF stretching influences the point at which stretch is perceived or tolerated. The mechanism(s) underpinning the change in stretch perception or tolerance are not known, although pain modulation has been suggested.
Proprioceptive neuromuscular facilitation training induced alterations in muscle fibre type and cross sectional area.
- N Kofotolis, I S Vrabas, and E Vamvakoudis
Br J Sports Med 2005 March; 39(3): e11, 2005
Objectives: To compare the effects of proprioceptive neuromuscular facilitation (PNF) and isokinetic training on fibre type distribution and cross sectional area of the vastus lateralis muscle. Methods: Twenty four male university students were divided into two equal groups: PNF training and isokinetic training (ISO). The training regimen for the PNF group consisted of three sets of 30 repetitions against maximal resistance, alternating two patterns of sequential movements of the right lower extremity: (a) toe flexion and ankle plantar flexion and eversion; (b) knee extension and hip extension, abduction, and internal rotation. The ISO group performed three sets of 30 repetitions alternating knee extension and flexion of the right leg at angular velocities of 180 and 90°/s in an isokinetic dynamometer (Cybex). Both groups trained three times a week for a total of eight weeks. Muscle biopsy specimens were obtained from the right vastus lateralis muscle before and after training. Results: The mean percentage area of type IIB fibre was significantly decreased (p<0.01) after eight weeks of PNF training, whereas that of type IIA fibre was significantly (p<0.05) increased. The mean percentage area of ISO trained type IIAB fibres exhibited an augmentative pattern (p<0.01) with a parallel reduction (p<0.05) in type IIA. Percentage fibre type distribution exhibited a similar pattern. Conclusions: Both PNF and ISO training alter fibre type distribution and mean cross sectional area. These changes occur in the type II fibre subgroup.
The effects of proprioceptive neuromuscular facilitation stretching on shoulder range of motion in overhand athletes.
- P V Decicco and M M Fisher
J Sports Med Phys Fitness, 2005 vol. 45 (2) pp. 183-187
AIM:The purpose of this study was to compare the effects of the contract-relax-contract (CRC) and hold-relax-contract (HRC) proprioceptive neuromuscular facilitation (PNF) stretching programs against a control, on external range of motion (ROM) of the shoulder in apparently healthy athletes. METHODS:The subjects were male and female adults between the ages of 25 to 50 years old. Subjects also had been involved in at least one overhand throwing sport (tennis, baseball, quarterback in football, etc.) in the past year. There were 30 participants whom were randomly assigned to 1 of 3 groups (CRC PNF, HRC PNF, control) with 10 subjects per group. Measurement of ROM for external rotation of the shoulder was performed prior to and after 6 weeks of training using a goniometer. The CRC and HRC PNF stretches were performed on subjects twice a week for 6 weeks. The statistical analysis conducted involved a 3×2 analysis of variance with the criteria for statistical significance set at p<0.05. Post hoc testing included paired t-tests and Tukey tests to pinpoint significant differences relative to the interaction between group and time. RESULTS:There was an increase in ROM from pretest to post-test for the HRC group (+13.50 degrees) and CRC group (+14.60 degrees), but not in the control group (+0.30 degrees). The improvement in ROM however, was similar between the HRC and CRC groups. CONCLUSIONS:The CRC and HRC PNF stretching techniques are effective at increasing external shoulder ROM when consistently performed 2 times a week for 6 weeks.
The effectiveness of 3 stretching techniques on hamstring flexibility using consistent stretching parameters.
- D Scott Davis, Paul E Ashby, Kristi L McCale, Jerry A McQuain, and Jaime M Wine
J Strength Cond Res, 2005 vol. 19 (1) pp. 27-32
This study compares the effects of 3 common stretching techniques on the length of the hamstring muscle group during a 4-week training program. Subjects were 19 young adults between the ages of 21 and 35. The criterion for subject inclusion was tight hamstrings as defined by a knee extension angle greater than 20 degrees while supine with the hip flexed 90 degrees . The participants were randomly assigned to 1 of 4 groups. Group 1 (n = 5) was self-stretching, group 2 (n = 5) was static stretching, group 3 (n = 5) was proprioceptive neuromuscular facilitation incorporating the theory of reciprocal inhibition (PNF-R), and group 4 (n = 4) was control. Each group received the same stretching dose of a single 30-second stretch 3 days per week for 4 weeks. Knee extension angle was measured before the start of the stretching program, at 2 weeks, and at 4 weeks. Statistical analysis (p < or = 0.05) revealed a significant interaction of stretching technique and duration of stretch. Post hoc analysis showed that all 3 stretching techniques increase hamstring length from the baseline value during a 4-week training program; however, only group 2 (static stretching) was found to be significantly greater than the control at 4 weeks. These data indicate that static stretching 1 repetition for 30 seconds 3 days per week increased hamstring length in young healthy subjects. These data also suggest that active self-stretching and PNF-R stretching 1 repetition for 30 seconds 3 days per week is not sufficient to significantly increase hamstring length in this population.
Acute Effects of Static and Proprioceptive Neuromuscular Facilitation Stretching on Muscle Strength and Power Output.
- Sarah M Marek, Joel T Cramer, A Louise Fincher, Laurie L Massey, Suzanne M Dangelmaier, Sushmita Purkayastha, Kristi A Fitz, and Julie Y Culbertson
J Athl Train, 2005 vol. 40 (2) pp. 94-103
Context: Stretching is commonly used as a technique for injury prevention in the clinical setting. Our findings may improve the understanding of the neuromuscular responses to stretching and help clinicians make decisions for rehabilitation progression and return to play.Objective: To examine the short-term effects of static and proprioceptive neuromuscular facilitation stretching on peak torque (PT), mean power output (MP), active range of motion (AROM), passive range of motion (PROM), electromyographic (EMG) amplitude, and mechanomyographic (MMG) amplitude of the vastus lateralis and rectus femoris muscles during voluntary maximal concentric isokinetic leg extensions at 60 and 300 degrees .s.Design: A randomized, counterbalanced, cross-sectional, repeated-measures design.Setting: A university human research laboratory.Patients or Other Participants: Ten female (age, 23 +/- 3 years) and 9 male (age, 21 +/- 3 years) apparently healthy and recreationally active volunteers.Intervention(s): Four static or proprioceptive neuromuscular facilitation stretching exercises to stretch the leg extensor muscles of the dominant limb during 2 separate, randomly ordered laboratory visits.Main Outcome Measure(s): The PT and MP were measured at 60 and 300 degrees .s, EMG and MMG signals were recorded, and AROM and PROM were measured at the knee joint before and after the stretching exercises.Results: Static and proprioceptive neuromuscular facilitation stretching reduced PT (P = .051), MP (P = .041), and EMG amplitude (P = .013) from prestretching to poststretching at 60 and 300 degrees .s (P < .05). The AROM (P < .001) and PROM (P = .001) increased as a result of the static and proprioceptive neuromuscular facilitation stretching. The MMG amplitude increased in the rectus femoris muscle in response to the static stretching at 60 degrees .s (P = .031), but no other changes in MMG amplitude were observed (P > .05).Conclusions: Both static and proprioceptive neuromuscular facilitation stretching caused similar deficits in strength, power output, and muscle activation at both slow (60 degrees .s) and fast (300 degrees .s) velocities. The effect sizes, however, corresponding to these stretching-induced changes were small, which suggests the need for practitioners to consider a risk-to-benefit ratio when incorporating static or proprioceptive neuromuscular facilitation stretching.
PNF Stretching and its Effects on Maximal Exertion Exercises.
- D Sikora, N C Giordano, and A Jones
J Undergrad Kin Res 2005;1(1):16-22, 2005
The purpose of this study was to see if there were any differences between PNF stretching and improvement on the 40-yard dash and in the vertical jump. To do so we took eight college football players and had them test out in both areas. The test subjects ranged from the ages of 18 to 20 years of age. The mean age of the test subjects was 19.4 with a standard deviation of 1.4. We did not take the height and weight of the players because we did not feel this was a necessary component of the research project. One test consisted of just warming up by running two laps around the track and then running and jumping. A week later we had them come back and do the same routine, but use PNF stretching after the warm-up laps. There was no significant difference in performance measurements between the warm-up vertical jump (m=26.25) and the warm-up, plus PNF stretching and 40-yard dash (m=26.31). T (14)= -.104, p>.05. There was no significant difference in performance measurements between the warm-up 40-yard dash (m=5.136) and the warm-up, plus PNF stretching and 40-yard dash (m=5.098). T (14)=.902, p>.05. This study demonstrates that an acute bout of PNF stretching does not enhance 40-yard or vertical jump performance.
Stroke rehabilitation conducted by PNF method, with and without the application of botulinum toxin.
- S Pasiut, M Banach, K Longawa, and F Windak
Medical Rehabilitation 2005, Vol 9, Nr 1, 2005
One of the most common diseases of the nervous system is stroke. Its most frequently occuring kinetic accompanied by an increase in muscular tension called spasticity. For patients and their carers these in many aspects of their everyday life, especially in locomotion. New ways need to be looked for to decrease or remove spasticity and restore the function which was disrupted. Therapy by botulinum toxin of decreasing spasticity to treat children with cerebral palsy having equines-varus foot, and it proves treatment of diseases with increased muscular tension. Owing to it, a range of mobility increases, for joints, which facilitates locomotion. This improvement is caused by both pharmacological action, and Neuromuscular Facilitation (PNF) is considered to be especially effective rehabilitation method based mechanisms. This method in the therapy of adults, along with the application of botulinum toxin, seems of the patient after stroke, which may be very important for secondary stroke prevention. The aim of influence of the therapy by PNF method associated with a botulinum toxin application on the patients lower limbs. During gait the patients had the flexion of ankle and knee joints measured by means of focus on the amplitude of angular values. All patients presented in this description of cases showed an measured parameters, in both a four-week and a three-month period after the therapy. The results show a randomized control studies of larger groups.
A comparison of a self-stretch incorporating proprioceptive neuromuscular facilitation components and a therapist-applied PNF-technique on hamstring flexibility.
- B Schuback, J Hooper, and L Salisbury
Physiotherapy, Volume 90, Issue 3 , Pages 151-157, September 2004
Objectives To compare the effectiveness of a self-stretch incorporating proprioceptive neuromuscular facilitation components (Group I) versus a PNF ‘Slow Reversal Hold Relax’(SRHR) technique applied by a physiotherapist (Group II) in comparison to a control group receiving no intervention. Design Subjects were randomly allocated to either one of the two experimental groups or a control group. Setting Treatment room at Queen Margaret University College, Edinburgh, Scotland. Participants Forty-two subjects between the ages of 20 and 55. Main outcome measures Range of hip flexion assessed by a passive straight leg raise measured at baseline and again following the intervention. Results The mean change in range of right hip flexion was found to be 9.6° (95% confidence interval 6.6–12.6°) in Group I and 12.6° (95% confidence interval 9.6–15.5°) in Group II. Post hoc analysis demonstrated Groups I and II to be significantly different to the control group (P<0.001). However, there were no significant differences when the stretching regimes were compared. Conclusions Both stretching regimes incorporating proprioceptive neuromuscular facilitation components resulted in a significant increase in hamstring flexibility when applied once for 2minutes. The clinical implications of the findings are discussed.
The relationship between isometric contraction durations during hold-relax stretching and improvement of hamstring flexibility.
- B P Bonnar, R G Deivert, and T E Gould
J Sports Med Phys Fitness, 2004 vol. 44 (3) pp. 258-261
AIM:Previous research suggests proprioceptive neuromuscular facilitation (PNF) stretching techniques produce greater increases in range of motion than static or ballistic. The purpose of this study was to determine the isometric contraction hold time that best produces gains in hip range of motion after a 3-s (3-HR), 6-second (6-HR), and 10-s (10-HR) hold-relax PNF stretch. METHODS:The experimental design was a within subjects repeated measures 2 factor (baseline and treatment) by 3 factor (3-HR, 6-HR, 10-HR) ANOVA. The dependent variable was hamstring flexibility as measured in degrees of passive hip flexion with the knee extended. Measurements were taken in a university athletic therapy clinic. Sixty active individuals without history of knee or hip injury volunteered for this study. Each subject was randomly assigned to a 3-HR, 6-HR, or 10-HR group for the hold-relax PNF stretch. All subjects were passively taken to the end range of motion 3 times and a goniometric measurement was taken. Each subject then performed the hold-relax PNF stretch 3 times with either a 3-HR, 6-HR, or 10-HR isometric contraction hold time and another goniometric measurement was taken. An average of each of these 3 trials was then calculated. RESULTS:The data analysis revealed a significant main effect difference (F(1,5 7)+/-633.97, p<.001, eta2=0.918) between the baseline and treatment measurements. There were no significant differences for the between groups (3-HR, 6-HR, 10-HR) main effect or for the interaction term. CONCLUSIONS:All 3 hold-time conditions produced significant gains in range of motion compared to baseline measurements. The application of the findings suggest that clinicians could choose any of the hold-times and produce the same result to patient hip joint flexibility.
Controlled warm-up intensity enhances hip range of motion.
- David L Wenos and Jeff G Konin
J Strength Cond Res, 2004 vol. 18 (3) pp. 529-533
Acute effects of active and passive warm-up, proprioceptive neuromuscular facilitation (PNF), and ratings of perceived exertion (RPE) were compared during hip-joint range of motion (ROM). Two active warm-up treatments included (a) achieving a respiratory exchange ratio (RER) of 1.00 and (b) achieving 60% of heart rate reserve (HRR). Hydrocollator pads (HP) served as the passive warm-up treatment. These treatments and a control were randomly assigned to increase hamstring muscle temperature of the dominant leg. Warm-up treatments were administered to 12 men (mean 25.3 years) with a minimum of 24 hours interspersed between each treatment. A timed PNF (slow-reversal-hold) technique was conducted after each warm-up treatment. Tukey tests (p < 0.05) showed ROM for RER (107.4 degrees) was greater than all other treatments. ROM for HRR (102.8 degrees) and HP (103.4 degrees) did not differ from each other but were greater than the control (98.8 degrees). Ratings of perceived exertion were lowest for RER (4.0) and highest for control (8.5). Ratings of perceived exertion for HRR (6.0) and HP (6.5) were similar. In conclusion, an active warm-up before PNF stretching appears to be the most effective treatment to increase hip ROM. Results of RPE reinforce that active warm-up reduces the resistance to stretch. In a field setting, it is estimated that a warm-up of 70% of HRR would duplicate the muscle readiness equivalent to an RER of 1.00 before PNF stretching.
Re-examination of the possible role of Golgi tendon organ and muscle spindle reflexes in proprioceptive neuromuscular facilitation muscle stretching.
- Gordon Chalmers
Sports Biomech, 2004 vol. 3 (1) pp. 159-183
Literature concerning the theoretical role of spinal reflex circuits and their sensorimotor signals in proprioceptive neuromuscular facilitation (PNF) muscle stretching techniques was examined. Reviewed data do not support the assertion commonly made in PNF literature that contraction of a stretched muscle prior to further stretch, or contraction of opposing muscles during muscle stretch, produces relaxation of the stretched muscle. Further, following contraction of a stretched muscle, inhibition of the stretch reflex response lasts only 1 s. Studies examined suggested that decreases in the response amplitude of the Hoffmann and muscle stretch reflexes following a contraction of a stretched muscle are not due to the activation of Golgi tendon organs, as commonly purported, but instead may be due to presynaptic inhibition of the muscle spindle sensory signal. The current view on the complex manner by which the spinal cord processes proprioceptive signals was discussed. The ability of acute PNF stretching procedures to often produce a joint range of motion greater than that observed with static stretching must be explained by mechanisms other than the spinal processing of proprioceptive information. Studies reviewed indicate that changes in the ability to tolerate stretch and/or the viscoelastic properties of the stretched muscle, induced by PNF procedures, are possible mechanisms.
Challenges for evidence-based physical therapy: accessing and interpreting high-quality evidence on therapy.
- Christopher G Maher, Catherine Sherrington, Mark Elkins, Robert D Herbert, and Anne M Moseley
Phys Ther, 2004 vol. 84 (7) pp. 644-654
Although there is a growing awareness of evidence-based practice among physical therapists, implementation of evidence-based practice has proved difficult. This article discusses barriers to access and interpretation of evidence. Some solutions are offered, including facilitating the publication of all research, use of an optimum format for reporting research, maximizing the efficient use of electronic databases, improving physical therapists’ skills in critical appraisal of published research, and fostering consumer access to evidence. These strategies and others discussed in the article might facilitate implementation of evidence-based physical therapy.
Effects of repetitive work on proprioception and of stretching on sensory mechanisms: implications for work-related neuromuscular disorders.
- M Björklund
Department of Surgical and Perioperative Sciences, Sports Medicine Unit, Umeå University, and Center for Musculoskeletal Research, University of Gävle, Umeå, 2004
The aims of the thesis were (i) to investigate the impact of repetitive low-intensity work exposure on proprioception and (ii) to examine effects of muscle stretching (especially sensory effects and effects on muscle nociception) and to relate its application to the prevention, alleviation and/or treatment of work-related neuromuscular disorders. The effects of low-intensity repetitive work on the shoulder proprioception were tested in healthy subjects. The effect of working time on the retention of subjective fatigue and their relation to changes in proprioception, and the immediate effect of stretching on shoulder proprioception were investigated. A new method to test the stretchability of the rectus femoris muscle was investigated for reliability and validity and used to assess the effects of a two-week stretching regimen on range of motion and on subjective stretch sensation. Finally, the interactions between innocuous muscle stretch and nociceptive chemical stimulation on discharge behavior of nociceptive dorsal horn neurons in the feline spinal cord were explored. The main findings were as follows: 1) The repetitive low-intensity work to fatigue diminished the shoulder proprioception; the working time as well as the retention of subjective fatigue were partly related to the extent of changed proprioception. 2) There was no effect of acute muscle stretching on the proprioception. 3) The new method for testing muscle stretchability proved valid and reliable. A two-week stretching regimen increased the tolerance to stretch torque, but the range of motion remained unchanged. 4) Half of the nociceptive dorsal horn neurons that responded to close arterial injections of bradykinin were modulated by muscle stretching applied directly after the injections. Altogether, the results give credence to the hypothesis of an involvement of sensory information distortion due to repetitive low-intensity work exposure in the development of work-related neuromuscular disorders. Increased tolerance to stretch torque may be an important mechanism in explaining improvements following stretch treatment. The spinal interactions between innocuous stretch and nociceptive muscle afferent inputs indicate a possible mechanism involved in stretching-induced pain alleviation.
Stretching: mechanisms and benefits for sport performance and injury prevention.
- P Weerapong, P Hume, and G Kolt
Physical Therapy Reviews Vol 9, no 4 (2004), pp 189-206, 2004
Stretching is usually performed before exercise in an attempt to enhance performance and reduce the risk of injury. Most stretching techniques (static, ballistic, and proprioceptive neuromuscular facilitation) are effective in increasing static flexibility as measured by joint range of motion, but the results for dynamic flexibility as measured by active and passive stiffness, are inconclusive. The mechanisms of various stretching techniques in terms of biomechanics and neurology, the effectiveness of the combination of stretching with other therapies such as heat and cold, and the effectiveness of stretching for performance and injury prevention are reviewed. The possible mechanisms responsible for the detrimental effects of stretching on performance and the minimal effects on injury prevention are considered, with the emphasis on muscle dynamic flexibility. Further research is recommended to explore the mechanisms and effects of alternative stretching techniques on dynamic flexibility, muscle soreness, sport performance, and rate of injury.
The immediate effects of soft tissue mobilization with proprioceptive neuromuscular facilitation on glenohumeral external rotation and overhead reach.
- Joseph J Godges, Melodie Mattson-Bell, Donna Thorpe, and Drashti Shah
J Orthop Sports Phys Ther, 2003 vol. 33 (12) pp. 713-718
STUDY DESIGN:Randomized controlled 2-group. pretest-posttest, multivariate study of patients with shoulder musculoskeletal disorders. OBJECTIVES:The purpose of this study was to evaluate the immediate effect of soft tissue mobilization (STM) with proprioceptive neuromuscular facilitation (PNF) to increase glenohumeral external rotation at 45 degrees of shoulder abduction and overhead reach. BACKGROUND:It is postulated that limitation in glenohumeral external rotation, when measured at 45 degrees of shoulder abduction, represents subscapularis muscle flexibility deficits and is associated with the inability to fully reach overhead. No research, however, is available to demonstrate whether intervention strategies intended to improve subscapularis flexibility and glenohumeral external rotation range of motion at 45 degrees of shoulder abduction will improve a patient’s ability to reach overhead. METHODS AND MEASURES:Twenty patients (10 males, 10 females; age range, 21-83 years) with limited glenohumeral external rotation and overhead reach of 1 year duration or less served as subjects. The subjects were randomly assigned to a treatment group, which consisted of soft tissue mobilization to the subscapularis and proprioceptive neuromuscular facilitation to the shoulder rotators, or a control group. Goniometric measurements of glenohumeral external rotation at 45 degrees abduction and overhead reach were taken preintervention and immediately postintervention for the treatment group or at prerest and postrest periods for the control group. RESULTS:The treatment group improved by a mean of 16.4 degrees (95% confidence interval [CI, 12.5 degrees-20.3 degrees) of glenohumeral external rotation, as compared to less than a 1 degree gain (95% CI, -0.2 degrees-2.0 degrees) in the control group (P < .0005). Overhead reach in the treatment group improved by a mean of 9.6 cm (95% CI, 5.2-14.0 cm) in comparison to a mean gain of 2.4 cm (95% CI, -0.8-5.6 cm) for the control group (P = .009). CONCLUSION:These findings suggest that a single intervention session of STM and PNF was effective for producing immediate improvements in glenohumeral external rotation and overhead reach in patients with shoulder disorders.
Dynamic evaluation and early management of altered motor control around the shoulder complex.
- M E Magarey and M A Jones
Man Ther, 2003 vol. 8 (4) pp. 195-206
Altered dynamic control appears to be a significant contributing factor to shoulder dysfunction. The shoulder relies primarily on the rotator cuff for dynamic stability through mid-range. Hence, any impairment in the dynamic stabilizing system is likely to have profound effects on the shoulder complex. The rotator cuff appears to function as a deep stabilizer, similar to the transversus abdominus and vastus medialis obliquus, with some evidence of disruption to its stabilizing function in the presence of pain. Similarly, serratus anterior appears to function as a dynamic stabilizer, also demonstrating altered function in painful shoulders. Examination of dynamic control begins with a detailed examination of posture, evaluation of natural movement patterns and functional movements and assessment of the specific force couples relevant to shoulder function. One useful strategy in management of altered motor control related to these force couples is that of training isolated contraction of the rotator cuff prior to introduction of loaded activity, together with facilitation and training of appropriate scapular muscle force couples–serratus anterior and trapezius, in relation to arm elevation.
Randomized clinical trial of therapeutic exercise in subacute stroke.
- Pamela Duncan, Stephanie Studenski, Lorie Richards, Steven Gollub, Sue Min Lai, Dean Reker, Subashan Perera, Joni Yates, Victoria Koch, Sally Rigler, and Dallas Johnson
Stroke, 2003 vol. 34 (9) pp. 2173-2180
BACKGROUND AND PURPOSE:Rehabilitation care after stroke is highly variable and increasingly shorter in duration. The effect of therapeutic exercise on impairments and functional limitations after stroke is not clear. The objective of this study was to determine whether a structured, progressive, physiologically based exercise program for subacute stroke produces gains greater than those attributable to spontaneous recovery and usual care. METHODS:This randomized, controlled, single-blind clinical trial was conducted in a metropolitan area and 17 participating healthcare institutions. We included persons with stroke who were living in the community. One hundred patients (mean age, 70 years; mean Orpington score, 3.4) consented and were randomized from a screened sample of 582. Ninety-two subjects completed the trial. Intervention was a structured, progressive, physiologically based, therapist-supervised, in-home program of thirty-six 90-minute sessions over 12 weeks targeting flexibility, strength, balance, endurance, and upper-extremity function. Main outcome measures were postintervention strength (ankle and knee isometric peak torque, grip strength), upper- and lower-extremity motor control (Fugl Meyer), balance (Berg and functional reach), endurance (peak aerobic capacity and exercise duration), upper-extremity function (Wolf Motor Function Test), and mobility (timed 10-m walk and 6-minute walk distance). RESULTS:In the intention-to-treat multivariate analysis of variance testing the overall effect, the intervention produced greater gains than usual care (Wilk’s lambda=0.64, P=0.0056). Both intervention and usual care groups improved in strength, balance, upper- and lower-extremity motor control, upper-extremity function, and gait velocity. Gains for the intervention group exceeded those in the usual care group in balance, endurance, peak aerobic capacity, and mobility. Upper-extremity gains exceeded those in the usual care group only in patients with higher baseline function. CONCLUSIONS:This structured, progressive program of therapeutic exercise in persons who had completed acute rehabilitation services produced gains in endurance, balance, and mobility beyond those attributable to spontaneous recovery and usual care.
Impact of prior exercise on hamstring flexibility: a comparison of proprioceptive neuromuscular facilitation and static stretching.
- Daniel C Funk, Ann M Swank, Benjamin M Mikla, Todd A Fagan, and Brian K Farr
J Strength Cond Res, 2003 vol. 17 (3) pp. 489-492
Position stands from the American College of Sports Medicine and the Surgeon General site a need for strategies capable of enhancing the effectiveness of stretching on flexibility and joint range of motion. One strategy for enhancing flexibility that has received anecdotal support but lacks substantial experimental evidence is the impact of prior exercise. This study compared 5 minutes of static stretching and proprioceptive neuromuscular facilitation (PNF) on hamstring flexibility performed with and without exercise. Forty undergraduate student-athletes participated in a repeated measure, counterbalanced experimental design. Within-group comparisons indicated that PNF resulted in a significant (p < 0.05) increase in flexibility after 60 minutes of exercise when compared with baseline (9.6%) and without exercise (7.8%). No differences were observed with static stretching across time. In addition, no differences were observed between the groups at any time point. Results demonstrated that PNF performed after exercise enhanced acute hamstring flexibility, and implementing a PNF stretching routine following exercise may augment current stretching practices among athletes.
Chronic flexibility gains: effect of isometric contraction duration during proprioceptive neuromuscular facilitation stretching techniques.
- Ann V Rowlands, Vicky F Marginson, and Jonathan Lee
Res Q Exerc Sport, 2003 vol. 74 (1) pp. 47-51
The aim of this study was to assess the effect of to isometic contraction durations during propiceptive neuromuscular facilitation stretching on gains inflexion at the hip. Forty-three women (M age = 20.0 years, SD = 1.3) were assigned to one of three groups: 5-s isometric contraction (5-IC), 10-IC, and control. Flexibility was assessed at baseline and Weeks 3 and 6. Analysis of covariance, controlling for pretest differences, showed a significant interaction, F(2, 33) = 44.1, p < .001. Flexibility was significant lower in the control group relative to the 5-IC and 10-IC groups and in the 5-IC group relative to the 10-IC group at 3 and 6 weeks (3 weeks = 101.2 +/- 1.4 degrees, 114.3 +/- 1.5 degrees, 120.5 +/- 1.3 degrees; 6 weeks = 103.0 +/- 1.4 degrees, 126.1 +/- 1.6 degrees, 133.3 +/- 1.4 degrees for control, 5-IC and 10-IC groups, respectively). A longer contraction time led to greater increases in flexibility.
PNF training and physical function in assisted-living older adults.
- D A Klein, W J Stone, and W T Phillips
Journal of Aging & Physical Activity;Oct2002, Vol 10 Issue 4, p476, 2002
The impact of proprioceptive neuromuscular facilitation (PNF) on physical function in assisted-living older adults (73-94 years old) was studied. A 5-week pretraining period consisting of weekly visits by trainers to participants preceded a 10-week training period of warm-up, PNF exercises, and cooldown. Training progressed from 1 set of 3 repetitions to 3 sets of 3 repetitions. Assessments were conducted at baseline (T1), postpretraining (T2), and posttraining (T3). Eleven of 14 volunteer participants completed the study. Physical function was assessed by range of motion (ROM), isometric strength, and balance and mobility measures. Repeated-measures ANOVA identified 6 measures (sit-to-stand, shoulder- and ankle-flexion ROM, and hip-extension, ankle-flexion, and ankle-extension strength) with statistically significant differences. With the exception of hip-extension strength, these measures were statistically significant from T2 to T3 in post hoc univariate tests. Results indicate that PNF flexibility training can improve ROM, isometric strength, and selected physical-function tasks in assisted-living older adults.
Original Research PNF Training and Physical Function in Assisted-Living Older Adults.
- D A Klein, W J Stone, W T Phillips, J Gangi, and S Hartman
Journal of Aging and Physical Activity 42(1), 95-102, 2002
The impact of proprioceptive neuromuscular facilitation (PNF) on physical function in assisted-living older adults (73−94 years old) was studied. A 5-week pretraining period consisting of weekly visits by trainers to participants preceded a 10-week training period of warm-up, PNF exercises, and cool-down. Training progressed from 1 set of 3 repetitions to 3 sets of 3 repetitions. Assessments were conducted at baseline (T1), postpretraining (T2), and posttraining (T3). Eleven of 14 volunteer participants completed the study. Physical function was assessed by range of motion (ROM), isometric strength, and balance and mobility measures. Repeated-measures ANOVA identified 6 measures (sit-to-stand, shoulder- and ankle-flexion ROM, and hip-extension, ankle-flexion, and ankle-extension strength) with statistically significant differences. With the exception of hip-extension strength, these measures were statistically significant from T2 to T3 in post hoc univariate tests. Results indicate that PNF flexibility training can improve ROM, isometric strength, and selected physical-function tasks in assisted-living older adults.
Effect of proprioceptive neuromuscular facilitation stretch techniques on trained and untrained older adults.
- R Ferber and D C Gravelle
Journal of Aging & Physical Activity;Apr2002, Vol 10 Issue 2, p132, 2002
The effects of proprioceptive neuromuscular facilitation (PNF) on joint range of motion (ROM) for older adults are unknown, and few studies have investi- gated changes in joint ROM associated with age. This study examined PNF stretch techniques’ effects on knee-joint ROM in trained (T) and untrained (UT) older adults. Knee-joint ROM was tested in T and UT adults age 45–55 and 65–75 years using 3 PNF stretch techniques: static stretch (SS), contract- relax (CR), and agonist contract-relax (ACR). The 45–55 UT group achieved significantly more ROM than did the 65–75 UT group, suggesting an age- related decline in ROM. The 65–75 T group achieved significantly greater knee-extension ROM than did their UT counterparts, indicating a training- related response to PNF stretch techniques and that lifetime training might counteract age-related declines in joint ROM. The ACR-PNF stretch condition produced 4–6° more ROM than did CR and SS for all groups except the 65–75 UT group, possibly as a result of lack of neuromuscular control or muscle strength.
A comparison of traditional prosthetic training versus proprioceptive neuromuscular facilitation resistive gait training with trans-femoral amputees.
- K Yiğiter, G Sener, F Erbahçeci, K Bayar, O G Ulger, and S Akdoğan
Prosthet Orthot Int, 2002 vol. 26 (3) pp. 213-217
Reports in the rehabilitation literature suggest that patients with trans-femoral amputation ambulate well after suitable prosthetic treatment. The effects of exercise protocols on function, however, have not been documented in this population. This study was conducted to compare the outcome of traditional and proprioceptive neuromuscular facilitation (PNF) techniques on weight bearing and gait. Fifty unilateral trans-femoral amputees who were attending for their first prosthesis, participated in this study. Amputees were randomly assigned into groups receiving the traditional training or PNF. Traditional treatment was consisted of weight-shifting, balancing, stool-stepping and gait exercises. In the other group the same activities were given by PNF. Amputees were trained 30 minutes daily, for a total of 10 treatments. Pre- and post-training assessment included weight bearing measurements by using two bathroom scales and time-distance characteristics of gait from footprints. A statistically significant difference was found in all parameters within the groups due to pre- and post-training evaluation data (p<0.05), but more obvious improvement was observed in the group who received PNF (p<0.05). The results of the study suggest that the prosthetic training based on proprioceptive feedback was more effective to improve weight bearing and gait when compared with a traditional programme.
Effects of proprioceptive neuromuscular facilitation on the initiation of voluntary movement and motor evoked potentials in upper limb muscles.
- Kuniyoshi Shimura and Tatsuya Kasai
Hum Mov Sci, 2002 vol. 21 (1) pp. 101-113
To better understand the mechanisms behind proprioceptive neuromuscular facilitation (PNF), an important method in motor rehabilitation, we investigated the effects of assuming a PNF posture relative to a neutral posture on the initiation of voluntary movement (Experiment 1) and the excitability of the motor cortex (Experiment 2) using a wrist extension task. The initiation of voluntary wrist movement was operationalized in terms of the electromyographic reaction time (EMG-RT), and the excitability of the motor cortex in terms of motor evoked potentials (MEPs). Compared to the neutral position, we found that (1) the facilitation position changed the muscle discharge order enhancing the movement efficiency of the joint, (2) the facilitation position led to a reduction in EMG-RT, the magnitude of which depended on the proximity of the muscle to the movement joint, and (3) MEP amplitude increased and MEP latency decreased in the facilitation position as a function of the proximity of the muscle to the joint. These findings corroborate the presumed effects of PNF and provide insights into the neurophysiological mechanisms underlying the PNF method.
Speed-dependent treadmill training in ambulatory hemiparetic stroke patients: a randomized controlled trial.
- Marcus Pohl, Jan Mehrholz, Claudia Ritschel, and Stefan Rückriem
Stroke, 2002 vol. 33 (2) pp. 553-558
BACKGROUND AND PURPOSE:A new gait training strategy for patients with stroke seeks to increase walking speed through treadmill training. This study compares the effects of structured speed-dependent treadmill training (STT) (with the use of an interval paradigm to increase the treadmill speed stepwise according to principles of sport physiology) with limited progressive treadmill training (LTT) and conventional gait training (CGT) on clinical outcome measures for patients with hemiparesis. METHODS:Sixty ambulatory poststroke patients were each randomly selected to receive 1 of the 3 different gait therapies: 20 subjects were treated with STT, 20 subjects were trained to walk on a treadmill with a 20% increase of belt speed over the treatment period (LTT), and 20 subjects were treated with CGT. Treatment outcomes were assessed on the basis of overground walking speed, cadence, stride length, and Functional Ambulation Category scores. RESULTS:After a 4-week training period, the STT group scored significantly higher than the LTT and CGT groups for overground walking speed (STT versus LTT, P<0.001; STT versus CGT, P<0.001), cadence (STT versus LTT, P=0.007; STT versus CGT, P<0.001), stride length (STT versus LTT, P<0.001; STT versus CGT, P<0.001), and Functional Ambulation Category scores (STT versus LTT, P=0.007; STT versus CGT, P<0.001). CONCLUSIONS:Structured STT in poststroke patients resulted in better walking abilities than LTT or CGT. This gait training strategy provides a dynamic and integrative approach for the treatment of gait dysfunction after stroke.
A study of the facilitation of respiration in myotonic dystrophy.
- Jennifer Nitz and Brandon Burke
Physiother Res Int, 2002 vol. 7 (4) pp. 228-238
BACKGROUND AND PURPOSE:Dystrophia myotonica or myotonic dystrophy is a progressive neuromuscular disorder in which patients demonstrate an irregular respiratory pattern and are particularly subject to cardiopulmonary compromise. The aim of the present study was to investigate the effects of both proprioceptive neuromuscular facilitation (PNF) and staged basal expansion (SBE) breathing exercises in subjects with myotonic dystrophy in two different positions: high support sitting and left side-lying. METHOD:A randomized, double-blind study design was used. Seven non-congenital myotonic dystrophy subjects took part in the study. Six 'treatment’ levels were applied to each subject: resting in high support sitting; resting in left side-lying; PNF of deep breathing in high support sitting; PNF of deep breathing in left side-lying; SBE in high support sitting and SBE in left side-lying. The outcome measures employed were arterial oxygen saturation (SpO2) and heart rate, as measured by oximetry and thoraco-abdominal motion (TAM), and respiratory rate, as measured by a pneumograph. RESULTS:The PNF technique was found to be the main contributor to improvement in SpO2 for subjects with myotonic dystrophy, where a 2.2% increase was found in the high support sitting position and a 2.6% increase was found in the left side-lying position. There was an increase of between 377% and 556% in TAM during application of both treatment techniques, in either the high support sitting or left side-lying positions. Respiratory rate declined between 15% and 30% immediately after treatment application and heart rate dropped slightly by between 0.2% and 4.1%. CONCLUSION:The present study provides objective evidence that application of these respiratory physiotherapy interventions elicits an improvement in respiratory function in subjects with myotonic dystrophy. Further research into the physiological effects of these techniques could explore the mechanisms responsible for improvement in respiratory indices.
Effect of PNF stretch techniques on knee flexor muscle EMG activity in older adults.
- R Ferber, L Osternig, and D Gravelle
J Electromyogr Kinesiol, 2002 vol. 12 (5) pp. 391-397
The effects of proprioceptive neuromuscular facilitation (PNF) stretch techniques on older adults are unknown and the physiological changes associated with aging may lead to differential responses to PNF stretching. Therefore, the purpose of this experiment was to examine the effects of PNF stretch techniques and EMG activity in older adults. Three PNF stretch techniques: static stretch (SS), contract-relax (CR), and agonist contract-relax (ACR) were applied to 24 older adults aged 50-75 years. The subjects were tested for knee extension range of motion (ROM) and knee flexor muscle EMG activity. The results indicated that ACR produced 29-34% more ROM and 65-119% more EMG activity than CR and SS, respectively. It was concluded that PNF stretch techniques can increase ROM in older adults. However, a paradoxical effect was observed in that PNF stretching may not induce muscular relaxation even though ROM about a joint increases. Care should be taken when applying PNF stretch techniques to older adults due to age-related alterations in muscle elasticity.
The application of the principles and procedures of PNF for the care of lumbar spinal instabilities.
- G Johnson and V S Johnson
Journal of Manual & Manipulative Therapy, Volume 10, Number 2, 2002 , pp 83-105(23), 2002
Proprioceptive Neuromuscular Facilitation (PNF) is a dynamic manual approach to the evaluation and treatment of the neuromusculoskeletal system. This treatment approach has broad application for patients with both neurological and orthopedic problems. The authors have developed a systematic protocol using the philosophy and procedures of PNF integrated with other manual therapy procedures for the care of lumbar instabilities. This article will present the history, philosophy, basic principles, and procedures of PNF and their use in the treatment of lumbar spine instabilities.
The short to medium term effectiveness of proprioceptive neuromuscular facilitation stretching as an adjunct treatment to cervical manipulation in the treatment of mechanical neck pain.
- L M Wilson
Dept of Chiropractic, Durban Institute of Technology, 2002
The purpose of this study was to determine the short to medium term effectiveness of Proprioceptive Neuromuscular Facilitaion (P.N.F.) stretching [using the Contract-Relax-Antagonist-Contract (C.R.A.C.) technique as an adjunct treatment to cervical manipulation in the treatment of Mechanical Neck Pain.
Chronic patellofemoral pain syndrome: alternatives for cases of therapy resistance.
- F Schneider, K Labs, and S Wagner
Knee Surgery, Sports Traumatology, Arthroscopy, September 2001, Volume 9, Issue 5, pp 290-295
This study compared the efficacy of two approaches to treating therapy-resistant patellofemoral pain syndrome. In a prospective randomized study 20 patients were treated for 8 weeks with 16 physiotherapeutic exercises on a neurophysiological basis (proprioceptive neuromuscular facilitation) while another 20 patients underwent a special training program using a special resistance-controlled knee splint for 15 min three times daily. We measured muscle activity on a Cybex 6000 and performed surface electromyography of the vastus medialis and vastus lateralis muscles. Anterior knee pain was assessed by the Bessette and Hunter score and a visual analogue scale. An increase in electromyographic activity in the vastus medialis muscle and significant improvement in individual comfort were observed only in those treated by knee splint. The knee splint thus proved more effective than proprioceptive neuromuscular facilitation for treating cases of patellofemoral pain syndrome resistant to conservative therapy.
Effects of the use of cross-education to the affected side through various resistive exercises of the sound side and settings of the length of the affected muscles.
- M Arai, H Shimizu, M E Shimizu, Y Tanaka, and K Yanagisawa
Hiroshima J Med Sci, 2001 vol. 50 (3) pp. 65-73
The purpose of this study was to determine what kind of resistive exercise of the sound limb causes the most effective cross-education, which is defined as the muscle activity of the unexercised limb during contralateral exercise, by analyzing the force and electrical activity of the affected muscle. Six orthopedic patients with unilateral lower extremity impairment that resulted in unexercised quadriceps muscles through treatment by immobilization were the subjects of this investigation. The effect of cross-education was determined by observing the maximal torque of the unexercised quadriceps (MT) and the integrated electromyograms of the unexercised rectus femoris at the time of the maximal response of the torque (IE). A double-blind experiment was conducted with eighteen randomly applied combinations, consisting of six different exercises and three different knee angles. The various resistive exercises on the sound side consisted of proprioceptive neuromuscular facilitation (PNF) movements, PNF positions, straight movements and straight positions in the sagittal plane. Both the mean percentage of the IE and MT were above 23% in the PNF movement, while a mean above 13% was not found in any of the other exercises. PNF movement combined with hip internal rotation was found to be significantly effective for inducing cross-education.
Effect of warm-up and flexibility treatments on vertical jump performance.
- J B Church, M S Wiggins, F M Moode, and R Crist
J Strength Cond Res, 2001 vol. 15 (3) pp. 332-336
Although different warm-up and flexibility routines are often prescribed before physical activity, little research has been conducted to determine what effects these routines have on athletic performance in activities. The purpose of this investigation was to determine to what degree different warm-up routines affect performance in the vertical jump test. The 40 female participants were asked to perform a general warm-up only, a general warm-up and static stretching, and a general warm-up and proprioceptive neuromuscular facilitation (PNF) on 3 nonconsecutive days. Each of the treatments was followed by a vertical jump test. A 1-way repeated-measures analysis of variance revealed a significant difference in vertical jump performance. A post hoc analysis revealed decreased vertical jump performances for the PNF treatment group. Based on the results of this study, performing PNF before a vertical jump test would be detrimental to performance.
Acute changes in hamstring flexibility: PNF versus static stretch in senior athletes.
- J B Feland, J W Myrer, and R M Merrill
Phys Ther Sport, 2001 vol. 2 (4) pp. 8-8
Few studies have reported on the amount of acute changes in flexibility of the hamstrings resulting from stretching prior to activity, and no studies of this nature have focused on an elderly population. Methods: Ninety-seven subjects (mean age=65 years, range 55-79 years) participating in the World Senior Games were randomly selected for participation in this study. Subjects were randomly assigned to either a control group (no stretching), or one of two treatment groups (contract-relax proprioceptive neuromuscular facilitation stretch [CRPNF], or a static stretch). Hamstring flexibility was measured with a Penny and Giles goniometer prior to and after one repetition of stretching lasting 32 seconds. Analysis: Differences in flexibility scores from pretest to posttest for control and two treatment groups were assessed using the Wilcoxon signed-ranks test. Pair-wise comparisons in median differences between groups were assessed using rank analysis of covariance and the Mantel-Haenszel statistic. Results: Flexibility scores for participants in each of the control and treatment groups significantly increased from pretest to posttest. However, the increase was much greater for those in the two treatment groups, with median differences of 1 degree in the control group, 5 degrees in the CRPNF group, and 4 degrees in the static group. Both gender and age influenced the median difference between CRPNF and static groups. Specifically, the median difference was significantly greater in the CRPNF versus the static group for men but not women. Similarly, the median difference was significantly greater in the CRPNF versus the static group for participants younger than age 65 but not aged 65 years or older. Conclusion: One repetition (32 seconds) of stretching provides an acute increase in flexibility of the hamstrings. CRPNF and static stretches significantly improve flexibility. For men and participants less than 65 years of age, CRPNF stretch appears more beneficial than static stretch. The benefits in flexibility between CRPNF and static stretches are similar for women and participant ages 65 years and older.
The rehabilitative therapy of patients with osteochondrosis of the cervical spine and manifestations of hypermobility bv means of therapeutic physical exercise.
- V A Epifanov and V V Shuliakovski
Vopr Kurortol Fizioter Lech Fiz Kult 2000 Jan-Feb;(1):8-11
The problems of cervical spine osteochondrosis with hypermobility are of great medical and social significance. Physical rehabilitation methods can improve effectiveness of basic drug therapy. These include isometric exercises, postisometric muscle relaxation, proprioceptive neuromuscular facilitation, postural exercises and special massage.
A kinetic chain approach for shoulder rehabilitation.
- J McMullen and T L Uhl
J Athl Train, 2000 vol. 35 (3) pp. 329-337
OBJECTIVE:To introduce an approach to shoulder rehabilitation that integrates the kinetic chain throughout the rehabilitation program while providing the theoretical rationale for this program. BACKGROUND:The focus of a typical rehabilitation program is to identify and treat the involved structures. However, in activities of sport and daily life, the body does not operate in isolated segments but rather works as a dynamic unit. Recently, rehabilitation programs have emphasized closed kinetic chain exercises, core-stabilization exercises, and functional programs. These components are implemented as distinct entities and are used toward the end of the rehabilitation program. DESCRIPTION:Kinetic chain shoulder rehabilitation incorporates the kinetic link biomechanical model and proximal-to-distal motor-activation patterns with proprioceptive neuromuscular facilitation and closed kinetic chain exercise techniques. This approach focuses on movement patterns rather than isolated muscle exercises. Patterns sequentially use the leg, trunk, and scapular musculature to activate weakened shoulder musculature, gain active range of motion, and increase strength. The paradigm of kinetic chain shoulder rehabilitation suggests that functional movement patterns and closed kinetic chain exercises should be incorporated throughout the rehabilitation process. CLINICAL ADVANTAGES:The exercises in this approach are consistent with biomechanical models, apply biomechanical and motor control theory, and work toward sport specificity. The exercises are designed to stimulate weakened tissue by motion and force production in the adjacent kinetic link segments.
The role of the sensorimotor system in the athletic shoulder.
- J B Myers and S M Lephart
J Athl Train, 2000 vol. 35 (3) pp. 351-363
OBJECTIVE:To discuss the role of the sensorimotor system as it relates to functional stability, joint injury, and muscle fatigue of the athletic shoulder and to provide clinicians with the necessary tools for restoring functional stability to the athletic shoulder after injury. DATA SOURCES:We searched MEDLINE, SPORT Discus, and CINAHL from 1965 through 1999 using the key words „proprioception,” „neuromuscular control,” „shoulder rehabilitation,” and „shoulder stability.” DATA SYNTHESIS:Shoulder functional stability results from an interaction between static and dynamic stabilizers at the shoulder. This interaction is mediated by the sensorimotor system. After joint injury or fatigue, proprioceptive deficits have been demonstrated, and neuromuscular control has been altered. To restore stability after injury, deficits in both mechanical stability and proprioception and neuromuscular control must be addressed. A functional rehabilitation program addressing awareness of proprioception, restoration of dynamic stability, facilitation of preparatory and reactive muscle activation, and implementation of functional activities is vital for returning an athlete to competition. CONCLUSIONS/RECOMMENDATIONS:After capsuloligamentous injury to the shoulder joint, decreased proprioceptive input to the central nervous system results in decreased neuromuscular control. The compounding effects of mechanical instability and neuromuscular deficits create an unstable shoulder joint. Clinicians should not only address the mechanical instability that results from joint injury but also implement both traditional and functional rehabilitation to return an athlete to competition.
Proprioceptive neuromuscular facilitation decreases muscle activity during the stretch reflex in selected posterior thigh muscles.
- A M Carter and S J Kinzey
Journal of Sports Rehabilitation, vol 9, pp 269-278, 2000
Context: Proprioceptive neuromuscular facilitation (PNF) is commonly used before competition to increase range of motion. It is not known how it changes muscle response to rapid length changes. Objective: To determine whether PNF alters hamstring muscle activity during response to rapid elongation. Design: 2 3 2 factorial. Setting: Laboratory. Participants: Twenty-four women; means: 167.27 cm, 58.92 kg, 21.42 y, 18.41% body fat, 21.06 kg/m2 BMI. Intervention: Measurements before and after either rest or PNF were compared. Main Outcome Measures: Average muscle activity immediately after a rapid and unexpected stretch, 3 times pretreatment and posttreatment, averaged into 2 pre- and post- measures. Results: PNF caused decreased activity in the biceps femoris during response to a sudden stretch (P = .04). No differences were found in semitendinosus activity (P = .35). Conclusions: Decreased muscle activity likely results from acute desensitization of the muscle spindle, which might increase risk of muscle and tendon injury.
Effect of manual therapy techniques on the stretch reflex in normal human quadriceps.
- D J Newham and E Lederman
Disabil Rehabil, 1997 vol. 19 (8) pp. 326-331
The effect of four manual therapy techniques on the quadriceps stretch reflex amplitude (elicited by mechanical vibration) was studied in a randomized, controlled trial in 120 (20 in each of six groups) healthy human subjects aged 18-64 years. Passive and active techniques were studied; each under static and dynamic conditions. The passive procedures were massage (static) and knee oscillation (dynamic) for 5 min. Active techniques involved eight repetitions of isometric quadriceps contractions (static) and leg extension (dynamic). The two static techniques had no effect on the stretch reflex amplitude. Both dynamic techniques caused a reduction (active by 25%, p < 0.00001 and passive 12%, p < 0.05). Only the active, dynamic technique caused a greater change than in the control group (p < 0.005). The effect lasted for less than 1 min. These data question the ability of such techniques to make clinically valid changes in motoneuron excitability. Further studies are required on those with neuromuscular pathology, who may respond differently to normal subjects.
Rhythmic facilitation of gait training in hemiparetic stroke rehabilitation.
- M H Thaut, G C McIntosh, and R R Rice
J Neurol Sci, 1997 vol. 151 (2) pp. 207-212
Experimental and control groups of 10 hemiparetic stroke patients each underwent a 6 week, twice daily gait training program. The control group participated in a conventional physical therapy gait program. The experimental group trained in the same basic program with the addition of rhythmic auditory stimulation (RAS). Patients entered the study as soon as they could complete 5 strides with hand-held assistance. The training program had to be completed within 3 months of the patients’ stroke. In the experimental group RAS was used as a timekeeper to synchronize step patterns and gradually entrain higher stride frequencies. Study groups were equated by gender, lesion site, and age. Motor function was assessed at pretest using Barthel, Fugl-Meyer, and Berg Scales. Walking patterns were assessed during pre- and post-test without RAS present. Pre- vs post-test measures revealed a statistically significant (P<0.05) increase in velocity (164% vs 107%), stride length (88% vs 34%), and reduction in EMG amplitude variability of the gastrocnemius muscle (69% vs 33%) for the RAS-training group compared to the control group. The difference in stride symmetry improvement (32% in the RAS-group vs 16% in the control group) was statistically not significant. The data offer evidence that RAS is an efficient tool to enhance efforts in gait rehabilitation with acute stroke patients.
Proprioceptive neuromuscular facilitation techniques in sports medicine: a reassessment.
- P R Surburg and J W Schrader
J Athl Train, 1997 vol. 32 (1) pp. 34-39
OBJECTIVE:The purpose of this survey was for comparison with a similar 1981 survey to determine if proprioceptive neuromuscular facilitation (PNF) techniques are being implemented in the same manner today. DESIGN AND SETTING:The survey was made available at the 1993 NATA Clinical Symposium. SUBJECTS:The subjects were 131 athletic trainers representing all major national athletic conferences who attended the 1993 NATA Clinical Symposium and who stated that they used PNF exercise in their practice. MEASUREMENTS:The survey consisted of 15 questions dealing with academic preparation, years of practice, scope and method of preparation in PNF, application of nine PNF techniques to various joints and regions of the body, and the most successful use of PNF techniques. RESULTS:PNF techniques are most frequently applied during rehabilitation of the knee, shoulder, and hip, similar to 1981 except that the use of these techniques during ankle rehabilitation has increased. In both studies, the most frequently used techniques were contract-relax and hold-relax. Two techniques not surveyed in 1981, contract-relax-contract and hold-relax-contract, are becoming techniques of choice for elbow, wrist, hip, and knee rehabilitation. The use of PNF techniques in the muscle re-education phase of rehabilitation is an application identified in this survey not cited by athletic trainers in the 1981 survey. CONCLUSIONS:Proprioceptive and kinesthetic deficits are known to occur after certain types of injuries, and the use of PNF techniques to correct these problems is a natural application A contemporary trend in exercise rehabilitation is multiplanar exercises, which are typified by PNF techniques.
The effects of neuromuscular stimulation-induced muscle contraction versus elevation on hand edema in CVA patients.
- P D Faghri
J Hand Ther, 1997 vol. 10 (1) pp. 29-34
The purpose of this study was to evaluate the efficacy of the use of neuromuscular stimulation (NMS)-induced contraction of the paralyzed muscles to produce an active muscle pump for removing excess fluid and compare its effect with elevation of the upper extremity. The effects of 30 minutes of NMS of the finger and wrist flexors and extensors were compared with the effects of 30 minutes of limb elevation alone. Each of eight cerebrovascular accident (CVA) patients with visible hand edema received both treatments, one on each of 2 consecutive days. Measures of hand and arm volume and upper and lower arm girth were taken before and after each treatment. Analyses comparing mean percentage change scores for both treatments showed large and significant treatment effects for all dependent measures. The finding suggests that NMS was more effective for reduction of hand edema than limb elevation alone for this sample of eight CVA patients.
Effects of contract-relax stretching training on muscle performance in athletes.
- M Handel, T Horstmann, H H Dickhuth, and R W Gülch
Eur J Appl Physiol Occup Physiol, 1997 vol. 76 (5) pp. 400-408
The effects of an 8-week unilateral contract-relax (CR) stretching training program (passive stretch after isometric contraction) on muscular performance were investigated in a group of 16 athletes. The flexibility, maximum torque and angular position as well as contraction work in movements of the knee joint were determined before training and after 4 and 8 weeks of training. The torque measurements were performed under isokinetic conditions, eccentrically at angular velocities of 60 degrees x s(-1) and 120 degrees x s(-1), isometrically at five different joint positions, and concentrically at angular velocities of 60, 120, 180 and 240 degrees x s(-1) using an isokinetic dynamometer. A surface electromyogram (EMG) of the thigh muscles (quadriceps and hamstrings) was recorded simultaneously. As compared to untrained control limbs, significant improvements in active and passive flexibility (up to 6.3 degrees in range of motion), maximum torque (up to 21.6%) and work (up to 12.9%) were observed, and these were especially pronounced under eccentric load conditions. A comparison between integrated EMG recordings during eccentric and concentric loads, as well as the interpretation of the training-induced changes in the EMG, suggest that muscular activity under eccentric loads may be impaired by mental processes.
A new dimension–proprioceptive training of the upper extremities and trunk. Case report of a 13-year-old tennis player after shoulder dislocation.
- A Stommel
Sportverletz Sportschaden, 1997 vol. 11 (1) pp. XV-XVII
Facial neuromuscular retraining for oral synkinesis.
- J S Brach, J M VanSwearingen, J Lenert, and P C Johnson
Plast Reconstr Surg, 1997 vol. 99 (7) pp. 1922-31- discussion 1932-3
The purpose of this paper is to describe the outcome of facial neuromuscular retraining for brow to oral and ocular to oral synkinesis in individuals with facial nerve disorders. Fourteen patients with unilateral facial nerve disorders and oral synkinesis who were enrolled in physical therapy for retraining were studied. Synkinesis was measured with quantitative video facial position analysis prior to the initiation of physical therapy and at regular intervals during retraining. Retraining included surface electromyographic biofeedback-assisted specific strategies for facial muscle reeducation and a home exercise program of specific facial movements. Twelve of 13 patients with brow to oral synkinesis and 12 of 14 patients with ocular to oral synkinesis reduced their synkinesis with retraining. Patients with a 1-year on greater duration of a facial neuromuscular disorder (excluding patients with unusually marked changes) demonstrated a significant decrease in brow to oral synkinesis and in ocular to oral synkinesis; there was a mean percentage decline in abnormal movement of 60.5 percent (SD = 26.48) and 30.1 percent (SD = 62.57), respectively. We conclude that brow to oral and ocular to oral synkineses associated with partial recovery from facial paralysis were reduced with facial neuromuscular retraining for individuals with facial nerve disorders.
Modification of reactivity by rhythmic neuromuscular stimulation.
- J Kunnemeyer and D Schmidtbleicher
Sportverletz Sportschaden, 1997 vol. 11 (2) pp. 39-42
The rhythmical neuromuscular stimulation (RNS) by Nasarov is a new method for optimizing performance. By transferring mechanical vibration to the tendomuscular system better coordination of peripheral and central nervous system could be achieved. A study with twelve healthy students of physical education dealt with the question of the effects of RNS on drop jumps. After 12 minutes application of RNS the performance drastically decreased. Jumping height lowered and ground contact time increased. Recordings of EMG revealed corresponding alterations in muscle activity, such occurring in overload situations. Plastic deformation of tendon collagen and neuromuscular adaptation as stiffness-reduction of gamma-modulation is discussed.
Proprioceptive reaction in the healthy and chronically unstable ankle joint.
- R Löfvenberg, J Kärrholm, and G Sundelin
Sportverletz Sportschaden, 1996 vol. 10 (4) pp. 79-83
Chronic lateral instability of the ankle, a condition with frequent ankle sprain episodes, difficulties to walk and run on uneven ground and often pain, occurs in 20-30% after acute ankle sprains. The treatment of CLI as well as of acute ankle sprains have more and more in addition to operative reconstructions been focused on proprioceptive training which is in concordance with the results of recent research results. The present study shows that the reaction time after sudden angular displacement of the ankle on a trapdoor is increased by approximately 15 ms in patients with chronic lateral instability compared to control persons. We conclude that delayed proprioceptive response to sudden angular displacement of the ankle can be one of the causes to chronic lateral instability of the ankle and that proprioceptive training should be included in the treatment of acute and chronic ankle disabilities.
The effects of muscle fatigue on and the relationship of arm dominance to shoulder proprioception.
- M L Voight, J A Hardin, T A Blackburn, S Tippett, and G C Canner
J Orthop Sports Phys Ther, 1996 vol. 23 (6) pp. 348-352
It is hypothesized that proprioceptive information plays an important role in joint stabilization and that muscle fatigue may alter proprioceptive ability. The purpose of this study was to determine what effect shoulder muscle fatigue has on glenohumeral proprioception and to examine the relationship between arm dominance and shoulder proprioception. Eighty subjects without a history of glenohumeral pathology participated. Each was seated on an isokinetic dynamometer with a randomly selected shoulder positioned in 90 degrees of abduction and elbow flexion. With vision blinded, the arm was passively positioned in 75 degrees of external rotation for 10 seconds, then passively returned to the neutral starting position. Three trials each of active and passive repositioning (2 degrees/sec) were recorded. Following a fatigue protocol, both active and passive repositioning were reassessed. Testing order was randomized. A significant difference was detected between pre- and post-fatigue scores. No significant difference was detected between dominant and nondominant extremities. No relationship between arm dominance and shoulder proprioception was established. It is concluded that shoulder proprioception is diminished in the presence of shoulder muscle fatigue, suggesting clinical rehabilitation protocols must emphasize increasing muscular endurance.
The comparative effectiveness of static stretching and proprioceptive neuromuscular facilitation stretching techniques in increasing hip flexion range of motion.
- R D Sundquist
Oregon State University, 1995
The lack of hamstring muscle group flexibility has previously been associated with a higher incidence of hamstring strains among athletes. Several stretching methods have been shown to increase hip joint range of motion (ROM); however, identification of an optimal stretching method has proven difficult. The purpose of this study was to find an optimal method of stretching to improve hip flexion range of motion. Forty-three female college students, ranging in age from 18 to 29 yrs., volunteered to participate in this study. The subjects were randomly assigned to one of three stretching groups: static, contract relax, contract relax agonist contract. The subjects’ maximal passive and active hip flexion ROM values were measured using an inclinometer. The subjects were stretched by the same partners at a rate of six days a week for a total of 20 treatments over a 23 day period. The selected stretching techniques produced significant pretest to posttest increases (p<0.02) in both passive and active hip flexion ROM. None of the stretching techniques improved passive or active hip flexion ROM significantly more the contract relax agonist contract technique producing an average increase of 17.6 ± 14.1 deg, and the contract relax technique resulting in an average increase of 12.0 ± 10.8 deg. A significant stretching technique x pretestiposttest interaction was found for the passive ROM values (p<.02). Scheffe’ post hoc analysis of simple interaction effects revealed that the static stretching technique improved posttest passive hip flexion ROM significantly more than the PNF contract relax stretching method (p<.05). The results suggest that all three stretching techniques selected for this study are effective in increasing hip flexion range of motion. Static stretching of the hamstring produced the greatest increases in both passive and active hip flexion ROM, but no optimal technique was identified.
Effects of PNF stretching phases on acute arterial blood pressure.
- W L Cornelius, R L Jensen, and M E Odell
Can J Appl Physiol, 1995 vol. 20 (2) pp. 222-229
This study examined acute systolic (SBP) and diastolic (DBP) blood pressure responses within passive and modified proprioceptive neuromuscular facilitation (PNF) stretching techniques. Nonhypertensives (N = 60) were assigned to one of three treatment groups. Group 1 employed an antagonist passive stretch (APS), 6-sec maximal voluntary isometric contraction (MVIC) of the antagonist, and subsequent APS. Group 2 employed an APS, a 6-sec MVIC of the antagonist, submaximal concentric contraction of the agonist, and APS. Group 3 was similar to Group 2, with the deletion of an MVIC prior to the concentric contraction. Blood pressures were obtained during rest, baseline following passive stretch, and at the end of the three phases of the PNF technique. Range of motion (ROM) data were collected for baseline and treatment in terminal hip flexion for each group. All PNF treatments were effective for increasing ROM. One or two trials of PNF improve ROM and avoid increasing SBP, while a third trial increases SBP.
The contributions of proprioceptive deficits, muscle function, and anatomic laxity to functional instability of the ankle.
- G Lentell, B Baas, D Lopez, L McGuire, M Sarrels, and P Snyder
J Orthop Sports Phys Ther, 1995 vol. 21 (4) pp. 206-215
Functional instability is a common complication following an acute ankle sprain. Three potential contributing factors underlying the ankle which chronically gives way are proprioceptive deficits, muscle weakness, and ligamentous laxity. This study’s purpose was to document the presence or absence of these concerns in a sample of subjects with unilateral functional ankle instability. Both ankles of 42 subjects were randomly assessed for passive movement sense into inversion and generation of peak torque by the evertors isokinetically. Thirty-four subjects were available for documentation of talar tilt of both ankles through inversion stress radiographs. Analysis found significantly greater mean values for passive movement sense and talar tilt for the involved ankles compared with the uninvolved, while no significant strength differences in peak torque of the evertors were present. Fifty-eight percent of the sample demonstrated clinical impairments in at least one of these three categories. In conclusion, deficits in passive movement sense and anatomic stability are greater concerns than strength deficits when managing the ankle with functional instability.
Neuromuscular coordination of squat lifting, I: Effect of load magnitude.
- J P Scholz, J P Millford, and A G McMillan
Phys Ther, 1995 vol. 75 (2) pp. 119-132
BACKGROUND AND PURPOSE:In this study, we examined changes in kinematic and electromyographic (EMG) measurements of the coordination (ie, the relative timing of joint movements and muscle activity) of a squat-lifting task in response to lifting increasing loads. SUBJECTS:Fifteen male industrial workers served as a sample of convenience. METHODS:Subjects lifted a weighted crate containing 15% to 75% of their maximum lifting capacity using a symmetrical squat-lift technique. Movement kinematics were obtained with videography. The relative phase between joint motions was derived. The EMG activity of the vastus lateralis muscle (VL) and the erector spinae muscle (ES) was recorded, and the relative timing of their onsets and peaks was estimated. RESULTS:The relative phase of movement between joints such as the knee and lumbar spine changed in a quasi-linear fashion with increasing load during lifting but not during lowering. The relative time of onset of ES EMG activity and its peak activity changed in a manner consistent with the interjoint relative phase results. The timing of VL events were not affected by increasing the load. CONCLUSION AND DISCUSSION:Relatively continuous changes in interlimb coordination occur when increasing the load lifted from an initial squatting posture. Changes in EMG relative timing partially corroborate the kinematic evidence for changes in coordination with load scaling. The results indicate the need for further study to determine whether the observed changes in coordination are beneficial or detrimental to the musculoskeletal system. Clinicians should evaluate performance of this task under a range of task conditions.
Neuromuscular coordination of squat lifting, II: Individual differences.
- J P Scholz and A G McMillan
Phys Ther, 1995 vol. 75 (2) pp. 133-144
BACKGROUND AND PURPOSE:This article reports individual differences in the coordination (ie, the relative timing of joint movements and muscle activity) of squat lifting identified by extended analysis of data reported in the authors’ companion article in this issue. SUBJECTS:Two post hoc groups of 6 subjects each were identified from the original sample of 15 subjects based on qualitative differences in knee-lumbar spine relative motion plots during load acceleration. METHODS:Subjects lifted a crate containing 15% to 75% of their maximum lifting capacity using a symmetrical squat-lift technique. Movement kinematic data were obtained with videography, and the electromyographic (EMG) activity of the vastus lateralis and erector spinae muscles was recorded with surface EMG. Measurements of coordination derived both kinematically and via EMG and the kinematic data were examined for group differences. RESULTS:Subjects in group 2 limited lumbar spine motion during load acceleration for all loads lifted, whereas those in group 1 limited lumbar spine motion more when lifting the heaviest loads. These differences were obvious both qualitatively, via knee-lumbar spine relative motion plots, and quantitatively, via measures of the relative timing of joint motions early in the lift. The effect of load on the coordination of these joints was the same for both post hoc groups after initial load acceleration. Significant differences in other kinematic measurements were also found between these groups. CONCLUSION AND DISCUSSION:Despite specific instructions about how to lift the load, individual subjects coordinated their joints differently during the initial, accelerative phase of squat lifting. Individual differences in coordination in response to load increases could be categorized into two patterns, although the data of 2 subjects were difficult to categorize and thus not included in these analyses. Whether the two dominant patterns have consequences for stress to the joints during lifting remains to be determined.
Effect of proprioceptive neuromuscular facilitation on the gait of patients with hemiplegia of long and short duration.
- R Y Wang
Phys Ther, 1994 vol. 74 (12) pp. 1108-1115
BACKGROUND AND PURPOSE:The immediate and cumulative effects of proprioceptive neuromuscular facilitation (PNF) applied to the pelvic region on the gait of patients with hemiplegia of short and long duration were studied. SUBJECTS:The subjects were 20 patients with hemiplegia of short duration (mean = 4.4 months, SD = 0.8, range = 2.8-5.6; n = 10) or long duration (mean = 15.4 months, SD = 1.7, range = 12.7-18.5; n = 10). METHODS:Each subject received a total of 12 sessions of PNF (three times per week), with each treatment lasting for 30 minutes. RESULTS:In subjects with hemiplegia of short duration, gait speed and cadence improved immediately after 1 session of PNF, and this improvement was further enhanced after 12 treatments. By contrast, subjects with hemiplegia of short duration. CONCLUSION AND DISCUSSION:These data suggest that (1) in both groups of patients with hemiplegia, the cumulative effects of PNF is more beneficial than the immediate effects, and (2) patients with hemiplegia of short duration respond to training sooner than do patients with hemiplegia of long duration, although the cumulative effects are similar for both groups.
Neuromuscular testing and rehabilitation of the shoulder complex.
- G J Davies and S Dickoff-Hoffman
J Orthop Sports Phys Ther, 1993 vol. 18 (2) pp. 449-458
The shoulder complex plays an integral role in performing an athletic skill involving the upper extremity. The intricacy of the neuromotor components controlling shoulder motion and athletic skill is an issue that the sports physical therapist deals with on a daily basis when rehabilitating athletic patients. The purpose of this article is to review neuromotor control of the shoulder complex and describe an exercise routine developed to enhance proprioception, kinesthesia, and neuromuscular control. Clinical research studies examining the strength of the rotator cuff and scapular stabilizers, in addition to joint position sense, are reviewed. The results of these studies are discussed as they apply to the exercises described in the article designed to improve dynamic stability. The results of these studies and implementation of these exercises will help the sports physical therapy clinician assist the athletic patient and improve dynamic and neuromotor control of the shoulder.
Techniques to improve function of the arm and hand in chronic hemiplegia.
- G H Kraft, S S Fitts, and M C Hammond
Arch Phys Med Rehabil, 1992 vol. 73 (3) pp. 220-227
We evaluated functional improvement in the upper limb of chronic (more than six months’ duration) stroke patients who received one of two electrical stimulation treatments, conventional treatment, or no treatment. Twenty-two right-handed patients were assigned to one of four groups studied for 12 months posttreatment. Subjects received (1) EMG-initiated electrical stimulation of wrist extensors (EMG-stim), (2) low-intensity electrical stimulation of wrist extensors combined with voluntary contractions (B/B), (3) proprioceptive neuromuscular facilitation (PNF) exercises, or (4) no treatment. Subjects were treated for three months. Before treatment, upon completion of treatment, and three and nine months after treatment, subjects were evaluated by the Fugl-Meyer (FM) poststroke motor recovery test and by grip strength. Subjects also attempted three Jebsen-Taylor hand function tests and a finger tapping test at the same evaluation sessions, but many were unable to complete these tests. During the course of treatment, FM scores of subjects receiving PNF improved 18%, B/B improved 25%, and EMG-stim improved 42%. The aggregate FM improvement of the treated groups was significant from pretreatment to posttreatment, and the improvement was maintained at three-month and nine-month followups (all p less than .005). The treated subjects’ improvement in grip strength was also maintained at both followups (p less than .10). In contrast, the control group showed no significant change in FM scores or grip strength. The four treated subjects who were able to perform the hand function tests and finger tapping at all four evaluations also improved on these tests.
Comparative study of static, dynamic, and proprioceptive neuromuscular facilitation stretching techniques on flexibility.
- RC Lucas and R Koslow
Percept Mot Skills, 1984 vol. 58 (2) pp. 615-618
63 college women served as subjects in this 7-wk. study examining the effects of static, dynamic, and proprioceptive neuromuscular facilitating stretching techniques on the flexibility of the hamstring-gastrocnemius muscles. Subjects were assigned to one of the 3 treatment groups and received treatment 3 days a week. A pretest, a midtest (after 11 treatment days), and a posttest (after 21 treatment days) were administered. Analysis of group and test effects was accomplished by using a 3 X 3 factorial design with the group factor nested and the test factor crossed. Post hoc analysis indicated that all scores significantly improved from pretest to posttest. The findings indicated all 3 methods of flexibility training produced significant improvements when pretest and posttest mean scores were compared.