Improving hamstring flexibility: therapeutic ultrasound or proprioceptive neuromuscular facilitation?

Introduction: Hamstring shortness can cause postural disorders and gait abnormality. Recently, different therapeutic interventions have been proposed to increase hamstring flexibility. The purpose of this study was to investigate the effects of Ultrasound (US) and Hold– Relax (HR) stretching techniques on hamstring flexibility.Materials and Methods: In this quasi-experimental study, thirty– six individuals with hamstring shortness were randomly assigned either to control, or therapeutic US, or HR stretching technique groups. Two groups followed their own specific treatment protocols for 8 weeks. Standard goniometer was used for measuring hip flexion and knee extension range of motion. Data were statistically analyzed via one-way ANOVA using SPSS software-version 19. Significance level was set at P < 0.05.Results: Study results showed that both treatment protocols significantly increased passive hip flexion range of motion (ROM) and passive knee extension ROM (P < 0.001). However, the HR technique had more significant efficiency as compared to US method (P < 0.001).Conclusion: It can be concluded that therapists can use both US and HR to improve hamstring flexibility. However, the HR method improves hamstring flexibility better than does US technique.Keywords: Hamstring shortness, Flexibility, Range of motion, Ultrasound, Proprioceptive neuromuscular facilitation