Center of mass location and segment angular orientation of below-knee-amputee and able-bodied children during walking.

This investigation compared the center of mass (COM) locations and segment angular orientations of the gait of below-knee-amputee (BKA) children to those of able-bodied (AB) children. Eleven AB children (mean age, 8.4 years) and three BKA children (mean age, 7.5 years) volunteered to participate as subjects. Film data (100 frames per second) of a typical walking stride, were collected for the children during four experimental sessions held at six-month intervals. Two 16mm cameras were used to obtain frontal and lateral views of the subjects. The same approximate rate of walking (1.2m/s +/- 10%) was enforced for all testing sessions and at least three trials of data were collected for each subject during each session. Segmental endpoints of each subject from the film of each camera were digitized and the direct linear transformation (DLT) method was used to obtain three-dimensional segmental location-time data for a complete stride. These data were then used to determine whole body COM locations and angular orientations for the segments. Discrete values describing normalized locations at touchdown, midsupport, and takeoff were determined for whole body COM and the angular orientation of the trunk, thighs, and legs. In the sagittal plane the COM was lower and more anterior for the BKA children when compared to that of the AB children. This was primarily due to the greater forward flexion of the trunk.(ABSTRACT TRUNCATED AT 250 WORDS)