Experimentally induced hypertrophy of growing voluntary muscle

Abstract

In one group of young rabbits the longitudinal growth of the belly of the tibialis anterior muscle was stimulated by transferring its tendon in front of the crural ligament and thus increasing the distance which it had to shorten in order to cause complete dorsi-flexion of the foot. The resulting increase in the final length of the muscle belly enabled it to exert iso­metric tetanic tensions comparable with those of the control through a greater range of lengths. In a second group of young rabbits the load on tibialis anterior was increased by eliminating the synergic muscle extensor digitorum longus. The growth in length of the muscle belly was not affected but it attained a greater girth and weight than the control. As a result, the isometric tetanic tensions which it could develop were increased but were exerted through a normal range of lengths.