PURPOSE: To characterize the EMG firing pattern of the biceps after transfer to the triceps. METHODS: Seven subjects (12 arms), 18.0 +/- 1.7 years old, consented to fine wire EMG assessment of the biceps, averaging 23.0 +/- 10.0 months (range: 9 to 45 months) after transfer. Subjects were tested under 3 conditions: (1) single flexion and extension, (2) self-selected alternating elbow flexion and extension, and (3) isometric flexion and extension. A strain gauge electrogoniometer measured elbow movement. Using root-mean-squared values of biceps EMG, ratios of extension/flexion activity were calculated for each muscle. Conventional manual muscle testing grades were obtained before and after surgery. RESULTS: Median manual muscle testing for elbow extension was 0 before surgery and 4- (range: 3- to 4) following surgery. For each of the 3 conditions tested, the biceps reversed its action to an elbow extensor (p < .05). CONCLUSIONS: Our findings show that the biceps, after transfer to the triceps in patients with C5 or C6 spinal cord injury, can be trained to activate preferentially during elbow extension, a reversal of its ordinary action as an elbow flexor.
PURPOSE: To characterize the EMG firing pattern of the biceps after transfer to the triceps. METHODS: Seven subjects (12 arms), 18.0 +/- 1.7 years old, consented to fine wire EMG assessment of the biceps, averaging 23.0 +/- 10.0 months (range: 9 to 45 months) after transfer. Subjects were tested under 3 conditions: (1) single flexion and extension, (2) self-selected alternating elbow flexion and extension, and (3) isometric flexion and extension. A strain gauge electrogoniometer measured elbow movement. Using root-mean-squared values of biceps EMG, ratios of extension/flexion activity were calculated for each muscle. Conventional manual muscle testing grades were obtained before and after surgery. RESULTS: Median manual muscle testing for elbow extension was 0 before surgery and 4- (range: 3- to 4) following surgery. For each of the 3 conditions tested, the biceps reversed its action to an elbow extensor (p < .05). CONCLUSIONS: Our findings show that the biceps, after transfer to the triceps in patients with C5 or C6 spinal cord injury, can be trained to activate preferentially during elbow extension, a reversal of its ordinary action as an elbow flexor.
Authors: Carrie L Peterson; Michael S Bednar; Anne M Bryden; Michael W Keith; Eric J Perreault; Wendy M Murray Journal: PLoS One Date: 2017-03-02 Impact factor: 3.240