Background and Aim: Several stretching methods have been shown to increase flexibility of the short muscles. Previous research suggests muscle energy techniques produce increments in range of motion, but there are many variations of muscle energy techniques. The purpose of our study was to determine the efficacy of muscle energy techniques with 50% of maximal voluntary isometric contraction and 10 second hold in compared to control group.

Materials and methods: A sample of 30 female subjects (aged 20 -25 years) participated in this study. All subjects had limited hamstrings flexibility in degrees of passive knee extension. The subjects in experimental group (n=15) received 3 muscle energy techniques (50% MVIC, hold time=10 sec) for 4 weeks, whereas the control group (n=15) remained without treatment. Before and after range of knee extension was measured for all subjects.

Results: The paired t test revealed a significant differences in flexibility for experimental group (P<0.001). There was no significant difference in flexibility gains in control group (P<0.001). Treatment group had significant greater flexibility than the control group (P<0.001).

Conclusion: Muscle energy techniques with above protocol produce an increase of hamstring flexibility.