1989 Volume 16 Pages 5-11
Two young cerebral palsied subjects with spasticity were given multi-site EMG biofeedback training in a kneeling posture. Surface electrodes were placed over the rectus femoris muscles and the biceps femoris muscles. The EMG signals were amplified and converted to a graphic pattern on a CRT controlled by a micro-computer. The graphic pattern was a cartoon character. The size of the character's face changed proportionally to the activity of the rectus femoris muscles and its nose changed in accordance with the activity of the biceps femoris muscles. The right and left of the face and nose corresponded, respectively, to the sudject's right and left side muscles. Subjects were instructed to draw a good graphic pattern on the CRT by maintaining body coordination. At the same time, binary feedback was used to monitor overall success during training. For each of the four muscle group / body side EMG channels, a threshold mean and standard deviation was computed for a baseline session. During training, the color of the cartoon character's nose and face changed to reflect success(white or blue) or failure(red or yellow) in meeting a criterion set for each channel. During the time all four criteria were met, a beep sounded repeatedly. Results showed that differential relaxation and tension of appropriate muscle groups were rapidly mastered during the training phase. After completion of training, the sudjects' posture without feedback was improved.