Reversal of antagonists: Effect on elbow extension strength and endurance

Objective: To evaluate the reversal of elbow antagonists designed to facilitate the extensors relative to agonist-only contractions of the extensors, while using a protocol previously demonstrated to result in an increase in strength through motor learning. Design: Two-group convenience sample composed of healthy subjects. Setting: Clinic research laboratory. Subjects: Twenty-eight healthy women without a history of upper extremity injury or neurologic disorder. Measurements: Elbow extension strength and endurance were measured during maximal effort isometric reversal of the elbow antagonists (experimental group) and elbow extension only (control group) resistance exercise. Biceps brachii short head (BBS), triceps brachii lateral head (TLAT), and triceps brachii long head (TLNG) electromyographic (EMG) activity was measured concurrently. Results: There were no significant differences between groups for either elbow extension strength, BBS, TLAT, or TLNG EMG activity. The experimental and control groups exhibited a significant linear (p < .01) and quadratic (p < .01) increase in baseline strength of 5.2N.m (30.5%). EMG activity from each muscle group increased linearly (p < .01) across all rest sessions, Similar results were observed for elbow extension strength and biceps and triceps EMG activity during fatigue testing. Conclusions: The reversal of antagonists technique was not superior to agonist-only resistance exercise, nor did it interfere with the acquisition of muscular strength or endurance through motor learning. (C) 1997 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.