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Updated: May 30, 2026
Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Immediate effects of quantified hamstring stretching: hold-relax proprioceptive neuromuscular facilitation versus
Emilio J Puentedura1, Peter A Huijbregts, Shelley Celeste
1Department of Physical Therapy, School of Allied Health Sciences, University of Nevada Las Vegas, USA. louie.puentedura@unlv.edu
Purpose:
To compare the immediate effects of a hold-relax proprioceptive neuromuscular facilitation stretching (HR-PNF) versus static stretch (SS) on hamstring flexibility in healthy, asymptomatic subjects.
Subjects:
Thirty subjects (13 female; mean age 25.7 ± 3.0, range 22-37) without excessive hamstring muscle flexibility were randomly assigned to one of two stretch groups: HR-PNF or SS.
Methods:
The left leg was treated as a control and did not receive any intervention. The right leg was measured for ROM pre- and post-stretch interventions, with subjects receiving randomly assigned interventions one week apart. Data were analyzed with a 3 (intervention: HR-PNF, SS, control) × 2 (time: pre and post) factorial ANOVA with repeated measures and appropriate post-hoc analyses.
Results:
A significant interaction was observed between intervention and time for hamstring extensibility, F(2,58) = 25.229, p < .0005. Main effect of intervention for the tested leg was not significant, p = .782 indicating that there was no difference between the two stretch conditions. However, main effect for time was significant (p < .0005), suggesting that hamstring extensibility (for both stretching conditions) after intervention was greater than before.
Conclusion:
No significant differences were found when comparing the effectiveness of HR-PNF and SS techniques. Both stretching methods resulted in significant immediate increases in hamstring length.
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