obtained. The ranges of limb rotations, however, were
not affected.
A summary of the results (range of motion) from
the present study along with the results from other
laboratories are compared in Table 2, where the
number of subjects is denoted by N. The age range
of subjects in all of these studies was approximately
similar. Results from this study are similar to results
reported by Sutherland et al. (23) at all of the joints
except the rotation angle of the pelvis. Specifically,
flexiodextension at hip, knee, and ankle joints was
quite similar. The difference in the range of pelvic
rotation may be due to the different definitions used
in measuring this angle. Sutherland et al. (23) defined
pelvic rotation based on the coordinates of the
tip and base of the sacral stick in a horizontal plane
while the same angle is defined as a third rotation in
the Euler sequence in our study. The range of motion
for the knee flexionextension angle in this
study was lower than those measured using goniometers
(5) and the reasons for this are not clear.
There were no other remarkable differences in joint
angles measured between this study and others
listed in Table 2.
In summary, we have described a system of measuring
three-dimensional angular motion of the pelvis,
thigh, shank, and foot based on a four-segment
rigid body model of the lower extremity. Embedded
coordinates were assigned to these segments based