Comparison of the effectiveness of two pelvic stabilization systems on pelvic movement during maximal isometric trunk extension and flexion muscle contractions.

Abstract

The purpose of this study was to compare the effectiveness of two pelvic fixation systems to limit pelvic movement during isometric trunk extension and flexion muscle strength testing. We developed a prototypal pelvic fixation system and compared it with a pelvic strap stabilization system. The prototypal pelvic fixation system consisted of fixation of the anterior superior iliac spines and sacrum, and the pelvic strap stabilization system consisted of a strap across the anterior superior iliac spines and a posterior pad. Small, but statistically significant, pelvic position changes occurred during isometric trunk extension and flexion muscle strength testing with the two stabilization systems. The pelvic angle changes were greater in extension than in flexion and greater when only the pelvic strap stabilization system rather than the prototypal pelvic fixation system was used. Our findings indicate that a more extensive prototypal pelvic fixation system minimizes pelvic movement to a greater extent during isometric trunk extension and flexion muscle contractions compared with the strap stabilization system.