Influence of thigh fluctuation upon pendulum-test waveforms

Abstract

Although pendulum-test is a simple and objective method to estimate spasticity by the use of the waveform of knee-joint pendulum motion, it isn't easy to unify lower-leg support situation at the beginning of its measurement without heavy burden on the subject. Large amount of fluctuation therefore exists in initial part of most waveform. We measured knee-joint angular velocity waveforms under the initial hip-joint positions of different angle as the first step to clarify its behavior. In each case, a damped oscillation was observed which constructed by 2~3 saw-tooth like spikes, and the higher the angle of the initial position was, the larger its amplitude became. Inverse simulation of the measured waveform showed that, the larger the initial angle of the hip-joint was, the larger the residual became. Present problem is to develop some way to be able to remove such an influence, reserving the present lower-leg support situation.