Abstract
The purpose of this study was to evaluate the short term effects of continuous passive range-of-motion exercise (CPROM-E) on passive resistive torque of the hip and knee. The subjects were 4 healthy adults and 6 spastic patients. During the CPROM-E, the joint angle and the load torque of the hip and knee were measured, and surface electromyogram of the vastus medialis and medial hamstrings was recorded. Peak torque of the joints or peak amplitude of the integrated electromyogram (I-EMG) was plotted against time of exercise, and the slope of the plots were analyzed by the t-test. In the healthy subjects, the peak torque of the hip decreased steadily and significantly (p<0.0001) by about 5 percent after CPROM-E, although the peak amplitude of I-EMG was not always reduced. In the spastic patients, the peak torque of the hip decreased significantly (p=0.01), by about 35 percent, and the peak amplitudes of I-EMG also decreased significantly (p=0.0003 and p=0.01, respectively). In one patient, the peak torque of the knee was analyzed and was found to decrease significantly (p<0.0001). However, there was no consistent change in the H-wave amplitude of the medial head of the gastrocnemius. Both reflex and non-reflex components of the joint resistance may play a role in reduction of the joint torque during CPROM-E.
