Reliability of the electromyographic assessment of the lumbo-pelvic extensor muscles activity during prone hip extension in athletes with hamstring strain injury

To investigate the intra-tester reliability of electromyographic (EMG) activity of lumbo-pelvic muscles during prone hip extension in subjects with chronic hamstring strain. A convenience sample of 10 athletes with history of hamstring strain injury. EMG signal amplitude (AMP) of the right and left erector spinea (RES, LES), gluteus maximus (GM), biceps femoris (BF) and semitendinosus (ST) was measured during prone hip extension (PHE) three times a day. The peak amplitude of the muscles was normalized to maximum voluntary exertion (MVE) of each muscle. Intraclass Correlation Coefficient (ICC) and Standard Error of Measurement (SEM) were used to assess the reliability. 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. 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.