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 > or = 1.06 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.

RELEVANCE: The present study shows that gait in healthy pregnancy is remarkably normal, but some differences in pelvis-thorax coordination were detected. In healthy pregnancy, anti-phase pelvis-thorax coordination appears difficult, but less so than in pregnancy-related pelvic girdle pain. Better understanding of gait in healthy pregnancy may provide insight into the gait problems of women with pregnancy-related pelvic girdle pain.