Experimental evidence from the dog, demonstrating the physiological importance of the multiple innervation to individual muscles, led to the detailed observations, here presented, upon multiple nerve branches in the human. Of fifty-eight separate heads of origin of the long muscles of the limbs in one cadaver, all but fifteen were entered by nerve branches at more than one point. Ten of these fifteen are known to receive more than one branch in Other individuals. These multiple branches may enter the muscle close together, or may be distributed for some distance over the length of the muscle. In neither pattern of branching can the ultimate distribution of the nerve fibers within the muscle be deduced from a purely morphological study.
The evidence obtained from experiments on the dog by Markee and Löwenbach demonstrates that the multiple nerves entering a muscle may control the contraction of different "segments" along the length of the muscle. The present study has emphasized that a similar anatomical condition exists in the human. However, physiological evidence similar to that for the dog has yet to be obtained.