Kinematic symmetry of the lower limbs.

This study examined the extent of kinematic symmetry of lower limbs when walking. Twelve able-bodied subjects were measured with a device which recorded three-dimensional motion of hip and knee joints bilaterally. Comparisons of right and left sagittal, transverse, and coronal plane motions were conducted in the time and frequency domains, and indices were developed to express these symmetries in each domain. In both domains high levels of symmetry were observed for the sagittal plane motions of hips and knees. High symmetry was also observed for the hip transverse and coronal plane motions, but symmetry was lower for these planes at the knee. Low standard deviations for the group occurred where symmetry was high. Reduced symmetry in the transverse and coronal planes was attributed to the lower signal to noise ratio for these planes. While experimental technique could be improved by better data collection procedures and by different analytic procedures, the study concluded that the able-bodied individual walks with reasonable symmetry at the hips and knees. These data formed a suitable baseline for comparison with pathologic gait data.