Effect of Active Dynamic Versus Passive Static Stretching on Hamstring Muscle Tightness in Healthy Female Students: A Randomized Trial Study

Background: For decades, static stretching has been the standard benchmark for training programs, because it has been shown to increase flexibility compared with other methods of stretching. Objective: The current study investigated and compared the effects of active dynamic stretching and passive static stretching on hamstring tightness. Methods: For this experiment, 64 female students were enrolled and randomly assigned to active dynamic or passive static stretching groups (n=32 each). The first and second experimental groups were trained with repetitive dynamic stretching and static stretching exercises, respectively. Exercises were performed 10 times per limb, 3 times per day, 5 days per week for 4 weeks. Hamstring muscle length measurements were repeated in weeks 2 and 4. Statistical analysis of the results was performed by t-test and repeated measures ANOVA using SPSS 15. Results: Both experimental groups showed significant improvements in the active knee extension range of motion during the intervention (P<0.001). However, active stretching showed better results and had a greater effect on range of motion in comparison with static stretching. Conclusion: Active dynamic training can be considered a suitable method for increasing the flexibility of the hamstring muscle and, consequently, reducing the complications and problems associated with hamstring tightness.