Agonist contractions against electrically stimulated antagonists

Abstract

Yanagi T, Shiba N, Maeda T, Iwasa K, Umezu Y, Tagawa Y, Matsuo S, Nagata K, Yamamoto T, Basford JR. Agonist contractions against electrically stimulated antagonists. Objective: To assess an exercise program that uses electrically stimulated antagonists to resist agonist muscle contractions. Design: In 1 limb, electrically stimulated antagonists resisted elbow flexion and extension. In the other, stimulation occurred without volitional muscle contraction. Setting: A biomechanics laboratory in Japan. Participants: Twelve men between the ages of 19 and 24 years. Subjects served as their own controls. Intervention: Subjects trained 3 times a week for 12 weeks. Each session consisted of 10 sets of 10 elbow flexor and extensor contractions. Main Outcome Measures: Isokinetic elbow extension and flexion torques. Biceps and triceps brachii cross-sectional areas. Results: Elbow extension torques increased (32.85% at 30°/s, 27.20% at 60°/s, 26.16% at 90°/s; all P≤.02) over the training period in limbs that trained against electrically stimulated antagonists. Control limb extension torque increases were smaller (8.52% –14.91%) and did not reach statistical significance. Elbow flexion torques improved in both groups, but the changes did not reach statistical significance. Cross-sectional areas increased in all muscles but were most marked in the antagonist stimulated limbs: triceps 16.20% versus 4.25% ( P=.01) and biceps 16.65% versus 7.00% ( P=.005). Conclusions: Exercises that use electrically stimulated antagonist muscles may be effective in increasing muscle strength and mass.