Agonist contractions against electrically stimulated antagonists¹

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.

Keywords:  Electric stimulation, Exercise, Muscles, Rehabilitation, Torque

• 1 No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.