Agonist contractions against electrically stimulated antagonists.

Abstract

To assess an exercise program that uses electrically stimulated antagonists to resist agonist muscle contractions. In 1 limb, electrically stimulated antagonists resisted elbow flexion and extension. In the other, stimulation occurred without volitional muscle contraction. A biomechanics laboratory in Japan. Twelve men between the ages of 19 and 24 years. Subjects served as their own controls. Subjects trained 3 times a week for 12 weeks. Each session consisted of 10 sets of 10 elbow flexor and extensor contractions. Isokinetic elbow extension and flexion torques. Biceps and triceps brachii cross-sectional areas. Elbow extension torques increased (32.85% at 30 degrees/s, 27.20% at 60 degrees/s, 26.16% at 90 degrees/s; all P<or=.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). Exercises that use electrically stimulated antagonist muscles may be effective in increasing muscle strength and mass.