Yet passive exercise is alone insufficient; for there are certain functions, such as that of muscular motion, which can be performed only through the agency of the will, and which will suffer if permitted to remain quiescent. Though the instruments of these functions may be invigorated, so far as their nutrition is concerned, by passive exercise, yet they will not operate efficiently for their peculiar purposes unless sustained in a due habit of action. On the whole, therefore, in order to strengthen a weakened system in all points, it is advisable to combine more or less together both kinds of exercise.

Partial or local weakness may always be treated with partial exercise, whether active or passive. Thus, a limb which has become enfeebled, and incompletely paralyzed by long rest, as, for example, an arm or a leg in which the muscles have been restrained by bandaging, may be restored to its original powers by constantly repeated efforts on the part of the patient to use it; and attention has already been called to a useful method of producing passive exercise of the stomach in pure dyspepsia.

The above remarks are applicable to the mental, or purely cerebral functions as well as to the others. These may also be divided into the active and passive, the former being voluntary, as the intellectual functions, the latter involuntary, as the emotional. In debility of the active functions, it is necessary, in order to restore due vigour, to exercise them actively through the will of the patient; in that of the passive, to exercise them passively, by so regulating extraneous influences as to excite them into operation.

It may be proper, before leaving the subject, to say a few words on the several varieties of exercise most resorted to in the treatment of disease.

Modes of Active Exercise

Modes of Active Exercise. Upon the whole, walking is probably the safest and most efficient mode of active exercise, in cases of simple general debility. It should be continued at one time no longer than may be sufficient to cause a slight sense of fatigue, and should be frequently repeated. The amount must, of course, be regulated by the strength of the patient. It should never, in debility, be so rapid as to induce much palpitation of the heart. When the weather is such as to forbid the invalid to walk in the open air, he should take the exercise within doors, throwing up the windows, so as to admit the fresh air, and maintaining a temperature in the apartment, somewhat below that which is comfortable to him when seated.

Other and more energetic modes of active exercise are running, leaping, wrestling; the various kinds of bodily labour; athletic games, as those of quoits, ball-playing, bullet-rolling, bar-pitching, etc.; and within doors, dancing, billiards, nine-pins, the use of dumb-bells, battledore and shuttlecock, gymnastics, calisthenics, etc. It is often necessary, in order that the invalid may be duly amused or interested, to vary the modes of exercise to suit his taste or caprices; and hence the propriety of having a considerable list out of which to choose. To those already mentioned, as suitable for patients confined to their houses, may be added, sawing and splitting wood, rubbing furniture, and various other household operations, which, by amusing the patient with the idea of usefulness, may lessen the irksomeness of the measure, considered merely in a therapeutic point of view. Indeed, this idea should be carried out in all plans of exercise. There should be some other ostensible object than that merely of improving health. The patient should, if possible, become interested in the act, occupation, or pursuit for itself alone. Other advantages of this diversity of plans are that, by a proper choice among them, we may duly proportion the activity of the exercise to the strength of the patient, and that, in consequence of the various muscles brought into play in the different methods, we may by successive changes operate on the whole system of voluntary muscles, or bring some particular method to bear upon special muscles or organs, which may stand peculiarly in need of invigoration. But in all the methods referred to, care must be taken to avoid excess; and this is particularly necessary of those which have in themselves something fascinating or seductive. Serious evils, for example, have sometimes arisen from the abuse of dancing, and gymnastic exercises.

The modes of exercise above referred to are often useful, not only by their tonic influence on the muscular system directly, and other systems indirectly, but also by a derivative influence, tending to draw away an excess of blood and nervous action from internal organs, congested or chronically inflamed Every one of sedentary and studious habits must have been sensible of the great relief, in instances of visceral uneasiness, or oppressed and clouded thought, afforded by rising and walking briskly for some time, or otherwise actively employing the voluntary muscles; and chronic inflammation of the liver, stomach, brain, etc., may often be greatly benefited by a systematic external derivation of the same kind.

Modes of Passive Exercise

Modes of Passive Exercise. Horseback exercise is probably the most effective, and generally applicable, of all the different passive methods. It is, however, too fatiguing for great debility. Moderate at first, it should be gradually increased with the increasing strength and tolerance; and a patient who has commenced with less than a mile, may often extend his rides to fifteen or twenty miles daily with propriety. It is more especially applicable to cases in which the abdominal or thoracic viscera are enfeebled. No remedy, probably, is more effectual in pure dyspepsia; and, since the times of Sydenham, it has been considered a most valuable prophylactic in phthisis. Indeed, there is reason to think that it often proves useful, and sometimes even curative, after the disease has actually commenced. Hepatic torpor without inflammation, habitual constipation from enfeebled function, and hemorrhoidal affections arising from one or both of the preceding conditions, are often benefited by this mode of exercise. The same may be said of headaches and other cerebral affections, purely functional, and connected with debility. In relation to riding on horseback, the remark before made as to the importance of combining other objects with the pursuit of health, is peculiarly applicable. I have been told that the late Professor Wistar, of Philadelphia, used to recommend his dyspeptic patients to ride out everyday to a certain chalybeate spring, several miles from the city; his object being much more the benefit of the ride than that of the waters. A long journey on horseback is an almost certain cure for pure dyspepsia.

Carriage exercise is more purely passive than that on horseback, for which, in its rougher modes, it is the best substitute. The jolting of a rough vehicle over smooth roads, or of a smooth vehicle over rough and stony roads, is often highly useful in the cases to which attention was called in the last paragraph. The jarring movement of the railroad car, and that of the steamboat, is next perhaps in efficiency to that just referred to. That of a row-boat is of the same character; and the exercise of the rower himself, combining the active and passive kinds, is an admirable measure for imparting vigour to the system, if not overdone. Riding in a smooth carriage and sailing are the mildest methods, applicable to the feeblest condition of system requiring exercise.

Substitutes for these methods may be found within doors. Chairs have been invented which enable the invalid to imitate horseback riding; and the same effect is in some degree obtainable by the jogging motion of an ordinary chair. The rocking-chair and the swing are partial substitutes for the smooth carriage and the sailing vessel; but, in these methods, it must be recollected that the peculiar character of the motion gives a special direction to the blood; in that of rocking centrifugally to the head, in that of swinging in like manner centrifugally from the head. From the former, therefore, injudiciously indulged in, there may be some risk of cerebral congestion; from the latter, of defective circulation in the brain.

Friction and shampooing may be considered as local varieties of passive exercise. Friction may be performed by the patient himself, in which case the active is combined with the passive, and more universal effects are obtained. It may be performed with the naked hand, or by means of flannel, a coarse linen towel, the flesh-brush, or any other roughish material; and should be carried so far as to excite some redness in the surface, but not to abrade or inflame it. The more extensively it is performed over the body the better; as its influence is thus proportionably generalized. It should be repeated once or twice daily in chronic cases. Shampooing is a practice introduced from the East, and consists essentially in a kind of kneading process, performed on the surface, but reaching in its effects deeper than mere friction, in fact throughout the soft parts of the body not protected by a bony case. Slapping over the surface with the sole of a slipper, or any slight flat body of a similar character, operates in the same way as the above processes. The effect of all of them is moderately to excite the surface and the soft parts near it, thereby attracting the blood and nervous action, and producing a tonic impression; while they operate derivatively in relation to the internal organs. They are, therefore, especially indicated in esses of torpor of the skin and muscles, attended with congestion or chronic inflammation of the viscera.