2008 Volume 32 Issue 4 Pages 221-228
Rehabilitation clinics strongly require easy and quantitative methods for evaluating patient's motion function. To answer such requirement, we developed a two-dimensional inverse dynamic analysis-based system, consisting of a CCD camera and a force sensor, for evaluating motor functions of upper extremity in hemiplegic patients. As a motor task, we asked patients to rotate a hinge lever with a constant torque, because most patients were able to carry out this simple task reproducibly. Subjects were 10 patients with slight spastic hemiplegia (the hemiplegic) and 10 normal people (the normal), and their range of motion (ROM), joint moment, and cooperative motion of neighboring joints were evaluated. Empirical results showed that both group had nearly the same joint trajectory, although the normal tended to use wrist joint more widely than the hemiplegic. Joint moment of the normal tended to be dominant in shoulder and elbow joints, while that of the hemiplegic was able to be classified into two patterns, dominance in shoulder and elbow joints like the normal and no significant contribution in these joints. In the normal group, joint moment of the elbow increased significantly in the initial phase of the task, followed by that of the shoulder. In the hemiplegic group, on the other hand, joint moment of the shoulder started to increase significantly at 20 degrees of the lever angle. All these results reflects the fact that the patients with hemiplegia were not able to selectively move all related joint voluntarily because of spastic paralysis. Consequently, the proposed analysis system can be considered to have a potential of clinically evaluating motor functions of upper extremity in slightly hemiplegic patients.
