Gait coordination in pregnancy: transverse pelvic and thoracic rotations and their relative phase

Objective. To examine the effects of pregnancy on the coordination of transverse pelvic and thoracic rotations during gait. Design. Gait of healthy pregnant women and nulligravidae was studied during treadmill walking at predetermined velocities ranging from 0.17 to 1.72 m/s. Background. Pelvis–thorax coordination during walking is altered in women with postpartum pregnancy-related pelvic girdle pain. This coordination has not been investigated in a healthy pregnant population. Methods. Comfortable walking velocity was established. Amplitudes of pelvic and thoracic rotations were calculated. Their coordination was characterized by relative Fourier phase and its standard deviation. Results. Comfortable walking velocity was significantly reduced. The amplitudes of pelvic and thoracic rotations were somewhat reduced, with significantly smaller intra-individual standard deviations. Also pelvis–thorax relative Fourier phase was somewhat smaller, its intra-individual standard deviation was negatively correlated with week of pregnancy, and significantly lower at velocities greater-or-equal, slanted1.06 m/s. Conclusions. The general pattern of gait kinematics in pregnant women is very similar to that of nulligravidae. Still, it appears that pregnant women experience difficulties in realizing the more anti-phase pelvis–thorax coordination that is required at higher walking velocities.