Seeligmüller quotes with approval Böttger's method for the treatment of deformities, where the weight of the body is utilized to stretch the retracted tendons. Thus, for talipes equino-varus an over-reduction is effected under ether, and the foot forced into a position of moderate calcaneo-valgus. In this position it is retained by the immediate application of a plaster or silica bandage. After this has hardened the child should be encouraged to walk in the mould, with the addition of felt shoes having a slanting sole that is thickened like a wedge at the inner side of the foot and strapped on like a skate. Then, during the act of walking the body tends to constantly force down the heel and thus stretch the retracted tendo Achillis, while the bandage and felt sole (acting like a splint) prevent the inner side of the foot from slipping up.
For talipes valgus the method is analogous, but the foot is forced into an equino-varus position, so that the tendo Achillis is artificially shortened, and ultimately becomes a rigid band, capable, in spite of the sural paralysis, of sustaining the heel.
A cause of relapse in talipes not unfrequently overlooked is the presence of even slight contractions of the hip- and knee-joints. These by shortening the limb tend to the production of equinus, since the foot points itself in order to reach the ground. These contractions, whose rigidity is far inferior to that induced by chronic arthritis, may be overcome by forced extension under ether or gradually by manipulations, or by the weight-and-pulley apparatus, applied in the recumbent position, as in morbus coxarius. The obvious objection to the latter method is the confinement in bed which it necessitates in a child enjoying at the time perhaps robust general health.
The contraction once overcome, the limb must be placed in apparatus which shall both maintain suitable extension and assist in supporting the trunk during station and locomotion. The latter purpose is effected, as in apparatus for chronic joint diseases, by transferring the weight of the body to steel splints running up each side of the limb, the outer one as far as a girdle which encircles the hips; the inner to a band surrounding the upper part of the thigh. Thus is extended the support which in paralysis limited to the leg-muscles is given by the steel splints inserted in the side of the club-foot shoes.
In the simplest form of apparatus locomotion is expected to be accomplished by the action of muscles inserted above the seat of the paralysis. Thus, when the muscles passing over the ankle-joint are paralyzed, the foot is moved as a dead weight by means of the quadriceps extensor, popliteus, and hamstring muscles inserted at the upper extremity of the leg. If the quadriceps cruris is paralyzed, the rotators of the thigh, ilio-psoas, sartorius, and adductor muscles, passing from the pelvis to the thigh, and which are so frequently intact in atrophic paralysis, are enabled to move the limb if the weight of the body is borne by steel splints, if these be light and properly jointed at the hip, knees, and ankle.182
182 Or the joint of the knee may be kept locked while the patient walks, when extension of the limb is mainly required, during both the active and passive movements of locomotion, the necessary flexion being supplied at the hip and ankle. By means of a key the knee-joint can be flexed during the sitting positions.
But an important aid to locomotion may be obtained from the artificial muscles, whose elastic tension is of such value in overcoming contractions. The quadriceps extensor, the most frequently paralyzed, may be supplemented by an India-rubber band and chain passing down the front of the thigh from a point on the pelvic girdle corresponding to the anterior iliac spine to a point on a leg-band, imitating the tibial insertion of the quadriceps tendon. Analogous bands stretched on the posterior aspect of the thigh simulate the hamstring muscles. When the external rotators are paralyzed, the artificial muscle must stretch from the pelvic girdle to a band encircling the upper part of the thigh.
The action of these muscles, apart from their elastic tension of repose, is thus explained by Duchenne: When any effort is made to move a paralyzed limb, the intact antagonists to the paralyzed muscles contract; thus, the flexors of the leg. But this contraction, being constantly opposed by the elastic tension of the artificial quadriceps, is restrained and gradual, instead of being brusque, jerking, and excessive, as it otherwise would be. This is the first result obtained. In the second place, contraction of the antagonist having ceased, the artificial muscle which has been stretched returns upon itself in virtue of its elasticity, and restores the limb to the position of normal equilibrium.
For the act of walking, however, the artificial quadriceps would require to be made tense enough to resist flexion, and thus keep the limb in extension. An artificial anterior tibial muscle, however, would require to yield to the intact gastrocnemius while the heel was being raised from the floor; then its elastic force should be sufficient to retract the point of the foot in dorsal flexion during the pendulum movement which passively swings the leg forward. The tension of the artificial muscle should therefore be so adjusted that it can only be overcome by the active contraction of the gastrocnemius, and at the moment of greatest tension, immediately after stretching, it should be able to quite overcome the gastrocnemius, then relatively183 relaxed.
183 We say relatively, believing that the simultaneous contraction of antagonist muscles has been well established as a constant normal phenomenon.