Effects of the pelvic rotatory control method on abdominal muscle activity and the pelvic rotation during active straight leg raising.

The aim of this study was to examine the effects of the pelvic rotatory control method on abdominal muscle activity and the amount of pelvic rotation while maintaining active straight leg raising (ASLR) at the level of the target bar. In this study, 27 healthy female volunteers were instructed to perform ASLR, ASLR with a pelvic compression belt, and ASLR with the pelvic rotatory control method. Surface electromyography (EMG) data were collected from the bilateral rectus abdominis (RA), external oblique abdominis (EO), and internal oblique abdominis (IO) muscles, and angles of pelvic rotation were measured using a 3-dimensional motion-analysis system. EMG activity of all abdominal muscles was greater and pelvic rotation was less in the pelvic rotatory control method compared with both the conventional ASLR method and the ASLR with pelvic compression belt method (p < 0.05). The findings suggest that ASLR with the pelvic rotatory control method is effective in activating the abdominal muscles and minimizing unwanted lumbopelvic rotation during ASLR exercise.