Dynamic pelvic stabilization during hip flexion: a comparison study.

Although physical therapists sometimes provide stabilization training for individuals with low back problems, research verifying the capacity of such training to alter pelvifemoral rhythm is lacking. This study was conducted to determine if pelvic movement could be limited by individuals who attempted active cocontraction of the abdominal and trunk extensor muscles during hip flexion. An experienced group consisting of 13 physical therapists familiar with stabilization training was compared with a novice group of 13 healthy individuals unfamiliar with such training prior to participation. All subjects were videotaped while supine, performing bilateral hip flexion. Trials were recorded both with and without attempts at limiting pelvic movement, which was digitized and analyzed from the videotape using the Peak 2-D Motion Measurement System. Inferential statistics, including a 2 x 2 x 2 analysis of variance and post hoc t tests, revealed that in the experienced group stabilization attempts resulted in significantly less pelvic movement. No significant differences were found between the stabilized and unstabilized trials of the novice group. The results of this study indicate that pelvic movement can be actively limited during hip flexion by physical therapists familiar with stabilization training. No subject, however, was able to eliminate movement.