Motion data were processed with
Visual3D software (CA-Motion Inc,
Germantown, Maryland) to produce
3-dimensional trajectories for
each marker. These data were filtered
with a 6-Hz Butterworth low-pass digital
filter. The position and orientation
of the trunk, pelvis, thigh, shank, and
foot segments in the laboratory coordinate
system were obtained, and
Visual3D algorithms were used to
determine trunk, pelvis, and lower
extremity joint angles for each percentage of the movement cycle.
Sagittal-plane trunk, pelvis, and thigh
orientations were expressed relative
to vertical, whereas hip, knee, and
ankle joint angles were generated by
their relative segments. Separate timenormalized,
ensemble-averaged joint
angle plots were created for each participant
and condition. Within these
ensemble plots the start, end, and
peak joint angle values were identi-
fied. Four group ensemble-averaged
profiles (CA, D-NE, D-BE, and D-CA)
were created for each joint angle.