Comparison of spine motion and trunk muscle activity between abdominal hollowing and abdominal bracing maneuvers during prone hip extension.

The aim of this study was to examine the effects of lumbopelvic stabilization maneuvers on spine motion and trunk muscle activity during prone hip extension (PHE). In this study, 14 healthy male volunteers (mean age, 21.2 ± 2.6 years) were instructed to perform PHE without any maneuvers (control), with abdominal hollowing (AH), and with abdominal bracing (AB). Surface electromyography data were collected from the trunk muscles and the lumbopelvic motion was measured. Lumbar extension and anterior pelvic tilt degree were significantly lower in the AH and AB than in the control condition during PHE (p < 0.001). Lumbar extension and anterior pelvic tilt degree did not differ significantly between the AH and AB (p > 0.05). Global muscle group activity such as external obliques was lower in the AH than in the AB. These findings suggest that PHE with AH effectively minimizes unwanted lumbopelvic motion which does not result in global muscle activation.