All that has been said of massage as an agent to assist the vascular system applies no less strongly when we consider its application for the benefit of the lymphatic circulation. Any toning up of the vaso-motor system that we can compass, and any assistance that we can give to the venous return, must, of necessity, tend to prevent the formation of oedema, and thus decrease any tendency there may be to stagnation in the lymphatics.

The pressure of lymph in the lymphatics is very low, and the lightest pressure must be all that is required to assist the onflow of the lymph under normal conditions.

But once oedema is present we have a pathological condition to combat, and it is well to remember that it is often possible to reduce an intense oedema by simple elevation. This reduction is, of course, transitory.

The following question sometimes arises: - "Why, if the process of emptying the lymphatic spaces is all that is required, should the result obtained by massage be more permanent than that of simple elevation?" The answer is simple. By elevation we can reduce the swelling, but we are doing nothing to remedy the cause of the swelling. By the use of massage we can assist the action of gravity very materially, and, at the same time, we can help to secure restoration of the tone of the vaso-motor system. The value of the scientific combination of elevation and rest, and of massage and activity in orthopaedic cases is dealt with in Chapter XXXII (The Combination Of Massage And Splintage In Orthopaedic Surgery).

Massage, however, can be invoked as a remedy calculated to secure the permanent relief of oedema, but it cannot do so if its effects are counteracted by neglect of reasonable postural treatment. It is also well to remember that oedema, as usually met with in cases recommended for massage treatment, is not due to disease of the lymphatic system, but is merely a symptom that "something has gone wrong" with the circulatory system.

Let us suppose that a rubber bottle filled completely by a sponge soaked in water is suspended by a string round its neck, and that we are asked to empty out the fluid content without disturbing the position of the bottle. The first thing we should do would be to take out the stopper and thus ensure there was no impediment to the outlet. Next we should place our hands on either side of the bottle near the top and squeeze out the water there; on relaxing we should squeeze somewhat lower and empty out, as it were, the next layer, and so on. It would be obvious folly to try to achieve our task while the exit was blocked, and pressure from below (unless the bag were practically full of water) would only result in pushing the water from the bottom of the bag to the top, allowing it to drop back again as soon as our pressure was relaxed. The parallel between the sponge in a rubber bag and the lymphatic system is not exact, but will serve.

If we wish to reduce oedema in a portion of a limb, the obvious course is to make sure there is no obstruction to the flow of the lymph in the proximal part. Let us then commence our massage above the level of the oedema and work gradually down towards the extremity - emptying a proximal space, filling it from the next more distal space, emptying it again, and so on.

Let us suppose that a leg is oedematous as high as the knee. Our first duty, as Wharton Hood has already expressed it, is to take the stopper out of the bottle by massage of the thigh. Then let us try to empty the contents of the lymphatics for, say, a hand's breadth below the knee into those above it, and we next ensure that the proximal channels are not overloaded by resuming massage of the thigh. Our next move is to restart massage of the leg another hand's breadth lower down. We empty this into the channels just below the knee, empty these in turn into the thigh, and once more see that these are not overloaded. In this way we can, by direct mechanical action, help to reduce oedema of the leg; but several days might elapse before our massage of the foot commenced. Were we to treat the foot before the leg had been fully prepared, the only result would be that the lymph in the foot would be squeezed into the already over-distended channels of the leg, where its onward passage would be impeded, with the inevitable result that it would return to the foot on the first opportunity.

In cases where the oedema is recent - however intense it may be - only a very gentle pressure need be exerted in our manipulations if the above plan of campaign is carried out faithfully. If the oedema is of long standing and of that tough, doughy consistency which the masseur so dreads to encounter, the exercise of a somewhat increased pressure may assist to clear the trouble more quickly, though our general plan should be adhered to in the main. A good working hypothesis which alone explains this need for greater pressure under these circumstances is as follows. The lymph, owing to long stagnation, has partially clotted, and has assumed a consistency more or less resembling treacle - just as happens in the synovial fluid of a knee-joint that has suffered from a long-standing synovitis. This thickened semi-solid lymph in the lymph spaces is too thick to pass through the minute stomata into the lymph channels. The heavier massage is required to break up the fine meshwork that has formed in the "clotted" lymph and to render it less "treacly." It is possible that our pressure may have the effect of producing a temporary paralytic dilatation of the arterioles, which, by causing a further outpouring of lymph, helps to dilute the now "sticky" lymph already present to such an extent that it is once more able to pass through the stomata into the lymphatic channels. Needless to say, this is purely a theoretical speculation as to what takes place. If it is true, it is obvious that no great pressure is required to break up the minute and very fragile fibrils in the presumed "semi-clotted" lymph; while the ease with which a transitory paralytic dilatation of the vascular system can be secured is shown by the readiness with which we can produce a flushing of the skin from this cause in response to very mild stimulation. But, be the explanation what it may, it is certainly erroneous to suppose that severe pummelling of a limb is necessary for the reduction of oedema. Such treatment is, in fact, detrimental. For the oedema to be present at all there must be some disorganisation in the vaso-motor system, and a severe handling will inflict an injury which the deficient circulation is already inadequate to repair. The possibility of such injury is still more obvious when we remember that we may simultaneously be damaging the vascular system by forcing the blood along the smaller arteries against the direction of flow and at the same time - perhaps even by this very action - causing a prolonged paralytic dilatation of the arterioles.

That too vigorous massage applied to an oedematous limb may fail to secure the desired result, while less forceful technique is crowned with success, is shown in the following instance, which is only one amongst many. An officer had been receiving massage treatment for many weeks before he came under my care. He told me that at first he laughed at the idea that our gentle handling could help him, when his former vigorous treatment had failed to do so. In a week he changed his mind on finding the circumference of his ankle reduced by over half an inch from the size it had maintained uniformly for many weeks. He added that he thought I was crazy when I first ordered massage to begin on the thigh when his trouble was in his foot!

The advice here given is in no wise to be regarded as a cloak for laziness on the part of the masseur. He who sits down and chats casually to his patient or stares about him while giving the treatment is neglecting his duty. A very considerable degree of concentration is essential, if the treatment of oedema is to be successfully performed. True, it is the sense of touch that controls the movements, but the fine distinctions that must be drawn to detect variations in consistency during treatment call for skilled work and close attention. Indiscriminate kneading and friction is not enough. At the upper level of the oedema general kneading is all that is required; as the level of the oedema is reached the firmness of the kneading should be increased. When the oedematous area itself is first treated the proximal part can be dealt with efficiently more easily than the next, and so on. When the level at which friction is first called for is reached, it may be necessary to apply it to one spot only. A little further down a considerable area may need to be dealt with in this way. Friction, kneading, stroking alternate with each other in ceaseless change and variation, but the changes must not be made promiscuously. At some definite moment friction should cease and kneading begin. If this moment is disregarded, too little or too much is done. So, too, with each of the other movements. The frictions should be performed with a rapidity that is excessively tiring, particularly if the pressure is properly graduated. The kneading should be less so, but none the less definite conscious effort is called for if the best is to be got out of the movement. The deep stroking is the least fatiguing; but it should serve only as a period of relaxed concentration, which will enable the masseur to recover, as it were, from his recent combination of mental and physical strain and to prepare for further effort. The time that should be devoted to the stroking is rarely, if ever, too long for this, and at the end of half an hour's work on an oedematous limb the masseur should have had enough. He should not be "done in" by physical exhaustion, but by the combination of physical work and mental concentration.