Naturally, a paralytic arm is used but little, or not at all, according to the degree of the injury; but a foot, if locomotion be feasible, will be used however ungracefully-and crutches are a last resort.

Now, how comes about the paralytic contracture? The theory common to the text-books is the so-called antagonistic," first clearly formulated by Delpech; according to it, the paralysis which leads to the deformity is partial, or at least unequal, and the muscles least weakened pull the limb to their side; this shortening, at first purely functional, becomes by and by structural, the muscle losing its capacity for extension, and thus retraction becomes contracture. This theory is tolerably simple. It asks only, what is the irritation which keeps the least injured muscle in a state of continual contraction; and the irritation is found in the so-called tonus. It takes for granted that the muscles enjoy continually a slight contraction, instigated by the nerves coming from the spinal marrow; as the mast of a ship is supported by the taut shrouds, and is pulled to the one side when the shrouds are let up on the other, so the limb is supported by the gentlycontracted opposite muscles, and drawn to the one side when the muscles of the other are relaxed.

Werner dodged the tonus theory, and slipped into another. He made the assertion that a muscle has the power to contract, but not to elongate itself, and that if an extensor be paralyzed, the limb will be fixed in flexion as soon as the patient attempts to use it, and will remain so until straightened by its own weight, by the hand, or other means; or at least the limb will

remain for a long time flexed. So the drawing up of the facial muscles of the sound side occurs, not at the moment of the opposite paralysis, but only with the first movement of the face.

The contracted muscles remain shortened because their antagonists fail to stretch them, and the weight of the cheek is not sufficient to do it.

Volkmann was deceived by this theory, and upon two occasions cut the contracted facials. He smoothed down the refractory cheek, and the deformity disappeared-so long as the patient could keep his face straight.

In a series of observations, Volkmann discovered that the worst forms of club-foot occur in complete paralysis of the leg; in complete paralysis of the forearm the worst forms of contractures of the hand and fingers ensue; in partial but extensive paralysis of an upper or lower extremity, it is not rare that just those muscles which lie in the normal curvature are most contracted (the antagonistic theory would require those on it); in case of paralysis of a single group of muscles, the deviation can be in the direction of the paralyzed muscles. Werner started right, but slipped

away.

Volkmann cites an illustrative case. A child was on the table to have the tendo Achillis cut on account of congenital club-foot. The foot projected beyond the table, and an assistant put the tendon upon the stretch; when it was cut the assistant let go, and the foot fell by its own weight into the worst equinus position. Supposing the muscle paralyzed, instead of the tendon

cut, the antagonistic theory would require a pes calca neus; and yet the actual fact suggested quite another explanation.

C. Hüter showed that the mass of the foot is so distributed in reference to the joint, that when the muscles are all relaxed it falls into a position of plantar flexion, with the inner edge of the foot higher than the outer (supination), and the great toe pointed a little inward (adduction); and this is exactly the position frequently observed in complete paralysis. And a deformity of the foot characterized by a similar position, may sometimes be seen after a compound fracture of the leg has been treated, not by splints, but by cradle or suspension.

In such cases there is developed a pretty obstinate form of pes equinus, and the sole of the unsupported foot is tilted into a varus position. Restitution gradually follows the attempt to walk. It is not rare to see that hollowness of the plantar surface of the foot which, in paralytic club-foot, is occasioned by the contraction of the plantar fascia; the weight of the point of the foot (the phalangeal and metatarsal regions) caused it gradually to sink, and then followed shortening of the muscles and soft parts. (Hüter.)

In consequence of long confinement in bed by severe internal disease, deformities of a similar kind are de veloped in the feet. Thus in a case of long-continued typhus and a relapse, when the patient was prepared to walk it was discovered that both feet were clubbed, and it required a year of orthopedic treatment. Here after we must consider this purely mechanical condition

an important factor in the commencement of the ordi nary form of club-foot.

But how to explain the opposite forms of pedal deformity, and not beg the active interference of the muscles? In studying the locomotion of paralytic children, Volkmann observed that instead of contractions about the knee-joint there is on the contrary a laxness, and a tendency on the part of the hip-joint to the same laxness.

In paralytics these two joints admit of movements in wider ranges than on the sound side. He observed also that the bending backward of the knee-joint (genu recurvatum) concurs with weakness of the quadriceps femoris, and in cases of complete paralysis about the knee. In such a case, the patient lying upon his back, the paralyzed limb assumes by its own weight a position so straight that the flexor muscles of the knee are even a little stretched. Let the patient stand upon a limb much weakened by paralytic affection of its muscles, and, if the knee be permitted to assume the normal slight flexion so nicely adjusted by the healthy quadriceps femoris, the balance is lost and the limb gives way. To preserve the equilibrium the patient seeks to plant the femur squarely upon the head of the tibia, and even allows the joint to settle backwards a little to rest against the ligamentous parts, which normal prevent re-flexion; and these ligamentous parts gradually yielding give rise at last to a genu recurvatum. The patient walks like one who has a stump in an artificial leg. As an illustration, Volkmann cites the familiar penknife. Open it and stick it perpen

dicularly in a board. Let vertical pressure be made upon the handle, and if the joint be the least open the blade will close. To prevent this, one is careful to keep the blade quite open, or even to press a little at the back of the joint.

In using an artificial leg, the knee-joint is manipulated by throwing the weight of the body before and behind the hinge, and station is easiest managed if the joint is made to close a little behind the vertical line. This seems to give the artificial limb a slight genu recurvatum; and this is no uncommon result in infantile paralysis. Volkmann has seen such cases, where the extensors were entirely paralyzed and the flexors intact, and others where the extensors were more or less weakened. The method of progression was always the same, the leg is brought well forward-sometimes with a dragging shuffle-and the weight of the body rests on the leg so that the knee is fully extended, the ligamentous structure preventing the joint from gaping backwards. The over-stretched and badly-nourished ligamentous parts gradually give way and a slight genu recurvatum is formed.

The hip-joint, after its fashion, suffers somewhat similarly. The lax ligamentous parts-although the capsule is re-enforced by the ligamentum Bertini-yield; the child acquires a halting gait, as in congenital luxation of the hip-joint. Thereby errors in diagnosis may occur, and Verneuil was deceived by this when he declared that the so-called congenital dislocation of the hip-joint is but a secondary effect of infantile paralysis. So we may explain certain paralytic deformities of