PNF Stretching Caleb Knight Ryan Maxfield PNF Stretch

PNF Stretching Caleb Knight Ryan Maxfield

PNF Stretch Overview � Proprioceptive Neuromuscular Facilitation � Combination of active and passive stretching � Used to increase ROM � Isometric Contractions: The joint angle does not change when the muscle contracts. � Isotonic Contractions: The resistance remains the same while the joint angle is allowed to change.

Overview Cont. � Reciprocal Inhibition: Contracting the opposite muscle to relax the muscle being stretched. � Autogenic Inhibition: Contracting the muscle being stretch to enable it to relax.

PNF Stretch Techniques Hold-Relax: 1. Passive Stretch of Agonist 2. Isometric Agonist Contraction 3. Relax 4. Passive Stretch of Agonist � Contract-Relax 1. Passive Stretch of Agonist 2. Isotonic Contraction of Agonist 3. Relax 4. Passive Stretch of Agonist � Slow-Reversal-Hold-Relax 1. Active Stretch of Agonist via Antagonist Contraction 2. Isometric Contraction of Agonist 3. Relax 4. Repeated Active Stretch �

Duration of Maintained Hamstring Flexibility After a One-Time, Modified Hold-Relax Stretching Protocol Purpose: To measure the length of time of increased ROM was sustained in the hamstrings after a 1 time hold-relax PNF stretch. Methods: � Subjects: 30 male military cadets � Test Procedure: Active Knee Extension ROM was measured prior to the Hold-Relax PNF stretch while the hip was maintained in 90 degrees of flexion and then at minutes 0, 2, 4, 6, 8, 16, and 32 after the stretch. � Conclusion: PNF stretch techniques increased hamstring flexibility with AKE but for only 6 minutes post stretch. � Critique: I feel this study was not very reliable or accurate. Military cadets are in much better shape than the rest of the normal population. This article was also performed 11 years ago. This study also did not study the functional effects of PNF stretching which would’ve given more evidence of what its contraindications and indications are. The study didn’t provide evidence that PNF is a better technique.

The Effects of a Warm-up on Acute Hip Joint Flexibility Using a Modified PNF Stretching Technique Purpose: To evaluate the effects of different warm-up techniques on performance of -PNF slow-reversal-hold-relax technique. Methods: � -Subjects: 54 healthy females between the ages of 23 and 38 with no injuries or abnormalities in the lower extremities and normal body fat measurements. � -Warm Ups: Each subject was randomly assigned to one of three 20 minute warm ups: Passive warm up in a whirlpool, active warm up on stationary bike, or no warm up (control) who sat for 20 minutes without activity. � -Measurement: Hip ROM was tested as well as knee extension with the Leighton Flexometer. � -Stretch Technique: The investigator performed a slow-reversal-hold-relax stretch protocol. Hip ROM was then measured via the Leighton flexometer 2 minutes after conclusion of warm up. Results: ROM did not change significantly with each group of warm ups so the warm up did not affect ROM when using the PNF slowreversal-hold-relax technique. Conclusion: PNF stretching directly increases ROM and flexibility but is not related to the introduction of active and passive warm ups. More research should be done to see how much ROM change occurs with warm ups combined with PNF stretching. Critique: This study was more reliable, the subjects were more related to the normal population and warm ups were assigned at random. There was no significant change in ROM with the different warm ups but we know that PNF stretching increases ROM. PNF coupled with active exercise provides the best result which is a very cost effective warm up. There was a control. There were also a greater number of subjects allowing more data to be collected. However this study is 20 years old.

� � � Purpose: Does PNF stretching effet peak torque, power output, AROM, PROM EMG, MMG, or isokinetic leg extensions? Subjects: 10 females and 9 males near 21 years old. Patients came in for two treatments during the study and were randomly assigned which stretch they received all were performed for 30 seconds. � Static: 1 active stretch and 3 different passive stretches. � PNF: 4 standard contract relax protocols. • Results: Static and PNF stretching decreased peak torque, mean power output, and electromyographic amplitude while increasing AROM and PROM. There was an increase in mechanomyographic amplitude in the rectus femoris only during the static stretch at 60 degrees per second. • Conclusion: PNF and static stretching both increased ROM but decreased strength, power outpt, and muscle activation for both velocities fast and slow. • Critique: This was the most recent study, there was a control, but there were not as many subjects. The equipment used was very objective and accurate. The article eluded to when PNF is beneficial and when it is not.

Indications � Beneficial in increasing -Muscle Tightness ROM

Contraindications � Post Operative � When using as a warm up for weight lifting or other power activities. � Use on unstable joints � Pre Activity or Competition

References O’Hora, J. , Cartwright, A. , Wade, C. D. , Hough A. D. , & Shum G. L. (2011). Efficacy of Static Stretching and Proprioceptive Neuromuscular Facilitation stretch on hamstrings length after a single session.

References Cont. 1. Spernoga SG, Uhl TL, Arnold BL, Gansneder BM. Duration of Maintained Hamstring Flexibility After a One-Time, Modified Hold. Relax Stretching Protocol. Journal of Athletic Training. 2001; 36(1): 4448. http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 155401/ Accessed November 4, 2012. � 2. Cornelius WL, Hands MR. The Effects of a Warm-up on Acute Hip Joint Flexibility Using a M 1 odified PNF Stretching Technique. Journal of Athletic Training. 1992; 27(2): 112 -114. http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 1317146/ Accessed November 4, 2012. � 3. Marek SM, Cramer JT, Fincher AL, Massey LL, Dangelmaier SM, Purkayasthma S, Fitz KA, Culbertson JY. Acute Effects of Static and Proprioceptive Neuromuscular Facilitation Stretching on Muscle Strength and Power Output. Journal of Athletic Training. 2005; 40(2): 94 -103. http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 1150232/ Accessed November 4, 2012. �