Objective: To investigate the intra-tester reliability of electromyographic (EMG) activity of lumbo-pelvic muscles during prone hip extension in subjects with chronic hamstring strain.

Materials & Methods: A convenience sample of 10 athletes with history of hamstring strain injury was studied. EMG signal amplitude of the right and left erector spinae, gluteus maximus, biceps femoris and semitendinosus was measured during prone hip extension three times a day. The peak amplitude of the muscles was normalized to maximum voluntary exertion of each muscle. Intraclass Correlation Coefficient (ICC) and Standard Error of Measurement were used to assess the reliability.

Results: The ICC values were greater than 0.90 for all tested muscles. The results indicate high reliability for EMG activity of the lumbo-pelvic muscles during prone hip extension in subjects with chronic hamstring strain.

Conclusion: The prone hip extension test can be used as a reliable method to assess the activity pattern of the lumbo-pelvic muscles in subjects with history of hamstring strain injury.