In human beings M. Castex found that when massage was begun early or from the very first in contusions, sprains, and dislocations not only were the immediate symptoms soon relieved, but also the subsequent serious consequences that are so apt to follow these injuries—wasting, weakness, contraction, and stiffness—were prevented. But when he tried massage in old cases of muscular atrophy or wasting following injuries to joints he got no increase of muscular tissue. The stiffness was got rid of; the muscles became suppler, but they still remained thin and lacking in strength. If he had combined passive and active movements with the massage he would probably have gained growth of muscle. He found that the galvanic and faradic currents were of benefit in promoting increase of muscular tissue. Muscular contraction produced by electricity is but another form of motion.
Numerous theories as to the cause of muscular atrophy from injuries to joints have been considered and abandoned. The most probable and most generally accepted is that of reflex action. The injury to the joint starts up more or less inflammation (arthritis); the articular nerves are irritated; this irritation is transferred to the spinal cord; the nerve centers affected act in turn upon the centrifugal nerves going to the muscles, and these determine at their peripheral ends the muscular atrophy. With a view to the elucidation of this, M. Deroche has repeated seven times, and always with the same results, experiments which were done for the first time at the College of France by MM. Raymond and Onanoff. He divided the posterior roots of the three last lumbar nerves on the left side in dogs and rabbits. After cicatrization had taken place he assured himself that numbness was complete from the thigh to the knee of the left lower limb, so that irritation of this region was not felt. The corresponding limb was left intact. An arthritis was then excited in both knees by introducing a thermo-cautery into them. No pain was felt in the left knee, but much in the right. Three months afterward the animals were killed, and in both knees the lesions of arthritis were found; but the muscles of the thigh of the left leg were of natural size; of the right, atrophied.
Prof. Simon Duplay and M. Cazin have also made a careful study of this subject in much the same way. Under the microscope they found that the articular filaments always presented signs of inflammation; but the large nerve trunks and spinal cord showed no appreciable change, and the results of the examination of the muscles were negative except as to diminution in size. They therefore concluded that muscular atrophies consecutive to joint injuries consist of simple atrophy, and that this can only be explained by a dynamic action, a simple reflex