The influences of foot placement on lumbopelvic rhythm during trunk flexion motion

Different standing postures could potentially influence trunk biomechanics during task performance. The current study investigated how foot placement, especially stance width and foot angle influenced lumbopelvic rhythm during sagittal trunk flexion motion. Ten participants performed pace controlled sagittally symmetric trunk flexion motions while maintaining three different stance widths and two different foot angles. The results showed the narrower stance and angled foot placement conditions generated more in-phase lumbopelvic coordination patterns during trunk flexion motions, possibly due to the reduced base of support and the associated postural stability. Findings of this study provided important information regarding the effects of foot placement on postural control and trunk biomechanics during trunk bending motions; these results suggested that foot placement could alter the motion patterns of spinal segments.