Biomedical Engineering Reference
In-Depth Information
interoperator variability in the orientation of the SCS about
the longitudinal axis is approximately 5° for the thigh and 9°
for the leg. The interoperator variability is also
approximately 9° for the foot segment. This study also
quantified the effect of these experimental errors on the joint
kinematics, which reaches 10° on the internal/external
rotation components of the knee and ankle. Other studies
tested the sensitivity of joint angles to the orientation of the
SCS, using mechanical systems [PIA 00] or numerical
simulations [KAD 90], and demonstrated a cross-talk
phenomenon, meaning that great care should be taken when
interpreting low-amplitude joint angles. In particular, the
accurate definition of the flexion/extension axis of the knee is
crucial [MOS 04], and the reproducibility of kinematic
results is improved when the flexion axis of the knee and the
center of the hip are obtained by the functional method
rather than using the anatomical landmarks [BES 03].
In conclusion, the experimental errors induce significant
uncertainty in the joint kinematics, which is difficult to
correct. Therefore, obtaining reliable results in a clinical
motion analysis context still requires significant research
efforts.
