In the previous chapter a general account has been given of the nature of re-education of muscle and also a rough sketch of the course to be adopted when undertaking it. Much still remains to be said, for the re-education of muscle is a distinct art which hitherto has received all too little attention. Indeed, only one book has been published which deals solely with muscle rest, muscle action and muscle training, and this is Colin MacKenzie's "The Action of Muscles." 1
At the present time there is still a most dangerous delusion which receives wide acceptation. This is that massage has the power of "working up a muscle." By this phrase, apparently, is understood that muscular strength can be restored or developed by massage alone. How utterly fallacious is this view can be shown by two simple reflections. First, were massage able to build up muscle strength, the finest athlete would at once become the one who could afford to employ the best masseur. Then, too, let anyone try to restore strength by massage to a limb which is wasted as the result of hysterical paralysis. No amount of massage will ever restore one iota of power. How, then, has the delusion arisen? Again the answer is quite simple. A patient, let us suppose, has suffered from a long and severe attack of typhoid fever. The lower limbs are wasted to a condition of almost complete impotence. Massage is ordered, and almost at once power returns and muscle is seen to re-develop. The massage gains the credit, and quite rightly, but the massage has only been the means by which the curative agency has been enabled to perform its task. What really has happened is this. Under the refreshing and invigorating effect of massage - smooth, gentle, rhythmical deep stroking and kneading - the muscles, which have lain passive for weeks, are encouraged to resume their normal functions of performing active movements, instead of continuing in their State of almost complete inactivity. It is this return of function, and this alone, that restores muscle strength and causes muscle development. This is what is meant in the preface when I wrote that massage can assist the recuperative course by reviving the power of spontaneous action. Massage alone, then, is all-insufficient to restore muscle strength; it can only incite, as it were, muscle activity. By assisting the circulation and the removal of waste products it can also aid a muscle to perform its function more freely than it can without it, but that is all. If a muscle does not know how to contract, no massage will ever teach it.
1 Published by H. K. Lewis & Co., London, 1918. In October, 1919, Prof. F. Wood-Jones dealt with "the voluntary muscular movements in cases of nerve injury" in his Arris and Gale lecture at the College of Surgeons of England. He therein ascribes a fourfold action to muscles, naming each muscle, according to its action, as prime mover, antagonist, synergist and fixation muscle. (See The Lancet, November 22nd, 1919.)
On the other side of the picture we have many and various so-called "systems" of exercise, of which I have selected the Swedish Educational and Remedial on which to pin my faith. These, one and all, presuppose that the muscles can, and do, perform their function; and even more, that they are fit and able to do so against the resistance of gravity for the most part. But a muscle that has been recently paralysed from disease, from nerve injury, or even if it has only undergone a marked degree of reflex wasting, may be totally unable to perform such a feat. Some system of education, therefore, is required to bridge the gap that exists between the period of complete paralysis or great weakness and the moment when a "set" exercise can be performed according to any of the established systems. This place is filled by muscle re-education.
To re-educate the muscle efficiently several definite principles must be realised and regarded.
First, an enfeebled muscle cannot contract unless and until its antagonist relaxes in conformity. The first thing to be done, therefore, is to teach the antagonist this, it may well be, difficult action. The simplest and best way is so to arrange the posture of the patient that gravity will oppose the action of the antagonist and assist that of the muscle we wish to train. The former is called upon to contract, and then the latter. If the movement is not performed we know that the antagonist has not relaxed; for, had it done so, gravity would have performed the movement independently of any assistive action from the muscle we hope to train. Until the movement is performed by gravity, all attempt at training the weakened muscle to contract is useless; as, if the antagonist has not learnt to relax sufficiently for gravity alone (or for the muscle we are training aided by gravity) to perform the movement, it is not to be expected that the muscle will be able to do so alone when the assistance of gravity has been withdrawn.
The second principle is to make sure that the patient's muscles at least know how to perform the movement we hope to see, and that he realises fully what is desired. This can only be done by placing the sound limb in the position we propose to choose for the re-education of its fellow, and by calling upon it to perform the movement possible as the result of the contraction of the muscles we are about to teach. When he has learnt on his sound limb what happens when he alternately contracts the muscle in question and then its antagonist, and that these actions can be done without strain or effort in other muscles or muscle groups - then, and then only, is it safe to make the attempt to copy in the damaged limb. It is often necessary to repeat this demonstration in the sound limb at frequent intervals throughout the training.
The third principle in muscle re-education is to ensure that, whatever task we set a muscle to perform (provided it has any power at all), we have every reason to suppose that it can do it; for enfeebled muscle seems to have this curious idiosyncrasy, that it will not even attempt to do that which it knows to be impossible. Rather will it remain completely flaccid and rely on synergist effort to perform the action demanded by volition. The result is often, indeed, the exact antithesis of what we expected; for it is no uncommon thing for the antagonist to be thrown into a condition of firm contraction. For instance, if we ask an enfeebled deltoid to abduct an arm which it is totally incapable of moving, the usual result is that the deltoid makes no effort whatsoever to secure gleno-humeral movement, but rather the adductors contract so as to do their best to assist the elevation of the arm by means of scapular movement in response to the command from the brain to abduct. It cannot be too fully realised that only movements are represented on the cerebral cortex and not individual muscle action. So it comes about that any impulse starting from the cortex leads to the contraction of muscle groups and not of individual muscles. This is one of the reasons that often render muscle-training after a tendon transplantation operation so difficult. Moreover, muscle action is not the simple thing we often suppose. Synergistic and antagonistic actions are still shrouded in half-revealed mystery. So it is not uncommon, if the muscles involved in "forming a fist" are excessively weak, that, in response to the call to perform the action, the arm is firmly adducted, the forearm is flexed and held rigid, the wrist springs back into dorsi-flexion, the interphalangeal joints are fully extended by the interossei, and nothing whatever happens in the direction of flexion of the fingers. To allow this sort of thing to go on is to impose a well-nigh insuperable obstacle to recovery. The secret of success is dual in character. First, we must so arrange the posture that the action which we wish to be performed can be carried through without undue effort or strain, even if we have to invoke the assistance of gravity in order to eliminate the necessity of synergist action. Second, we must ensure that only two muscle groups act within the limb, namely, the muscle we wish to contract and its antagonist. We must, in other words, strenuously combat the apparently uncontrollable instinct on the part of the patient's muscles to make too great an effort to secure the end in view. An enfeebled muscle is terribly handicapped in its earliest attempts at contraction by over-zealous efforts of other muscles throughout the limb. Effort - strong, persevering, repeated, voluntary effort - is the essential outcome of skilled muscle re-education; but the effort must be properly directed to secure the end in view, and not waste itself in a general wild, spasmodic activity that will probably suffice to produce any and every action save only the one we desire. If this tendency towards waste of energy is not strenuously combated, we often see a chaotic sort of attempt at movement which has led me to refer to it as the result of "confusional insanity of muscle."