The stepping movement is entirely difffferent movement from walking, and observation of the body's rotating movement around the long axis of the body is Important. We, therefore, test-erected a “Kinetogravicorder” and collected data from 20 healthy men and 19 patients with Parkinson's disease for analysis and comparison.
This method enables us to observe body movement as the movement of the center of gravity (which had only been visually observed in the past) is 2-dimentional recording of time passage.
It was observed that a healthy person's stepping movement showed two-peaks in the Y-component recording, which showed movement of the center of grarity, the large peak occuring when the feet wereshifted from the left to right and the small peak showing the shift of the center of gravity within the foot sole when the foot touches the floor board. The left to right movement (X-component) was in the shape of flattenid sign curve, which represented the length of time the foot sole stayed on the floor and length of time needed for shifting from one foot to the other. of these contact duration and swing duration, the contact duration seemed to be signifcantly controlled by the central programing as evidenced in the loaded rhythm, etc.
When the Tibial nerve was electrically stimulated to bring about spasms in the lower limb muscles and then the stepping movement was ordered, the small peak of the Y-component became deviated or disappeared.
The stepping patterns of the patients with Parkinson's disease were abnormal in both the contact duration and swing duration, and the two-peak pattern was also different from that of normal people's, . This deviation of the two-peak pattern in the Y-component in Parkinson's disease was characterized by the lack of the small peak which is mainly related to the foot joint movement. We suspect that in Parkinson's disease input information of voluntary movements of joints and muscles function as irregular information for the VIM nucleus as well as for some other central movement systems. in such a way that it provides a possibility for parkinsonian patients to protect themselves by making the foot joint movement steady.
