EFFECT OF POSITION ON MIGRATION OF MUSCLE

Abstract

The method of attachment of muscles to bone and the manner and control of migration of muscles during bone growth has received relatively little attention. These experiments were designed to test the hypothesis that a muscle''s ability to migrate is under control of that muscle and the bone segment to which it is attached, and is not a general property of either bone or muscle. The tibial insertion of the m. [musculus] semitendinosus of young rabbits was moved to a new location on the shaft of the tibia, either 5 or 10 mm proximal, or 0, 10, 20, 30, 40 or 50 mm distal to its original position. The animals were sacrificed 8 1/2 mo. later. The greatest amount of proximal migration of the experimental muscles was 11.3 mm in the muscles moved 10 mm distally. This compares to a migration of 12.8 mm for control muscles. The amount of proximal migration decreased progressively in either direction from this peak in the 0 mm, the 5 mm proximal, and the 20 and 30 mm distal groups. There was a small amount of distal migration in the 10 mm proximal and 40 and 50 mm distal groups. These results confirm earlier experiments in which muscles were moved only as far as 20 mm distally, and appear to support the hypothesis. This work has potential significance in evolutionary morphology and orthopedics.