Pelvic Rotation

Forward rotation of the pelvis on the swing side prevents an excessive drop in the body's center of gravity during periods of double limb support.

If the pelvis does not rotate, the COG's position is somewhat lower during periods of double limb support, and the COG's total vertical amplitude is greater.

The pelvis rotates forward on the swing side, then rotates relatively backward during stance.

0 %	L initial contact
50 %	R initial contact
100 %	L initial contact

The data are from a gait laboratory. The subject's pelvis appears to rotate in the transvserse plane around an angle that does not equal zero. This may reflect an actual asymmetry in the subject's rotation, or it may reflect the way the researchers' placed reflective markers on the subject's two ASIS.