heel; and in the sole of the foot, flexor brevis digitorum, which is instrumental in causing the metatarsal bones to assume a vertical position: they likewise produce retroversion of the foot, and tend to contract the longitudinal arch. And together with retraction of the last-mentioned muscle the plantar fascia is always contracted. But, although these are the agents which chiefly produce talipes equinus, other structures on the dorsum and in the sole of the foot subsequently become implicated; those in the sole, muscles as well as ligaments, being contracted, while on the dorsum they are in the same ratio elongated.

Atrophy of the muscles of the calf of the leg commences before the most severe grade of distortion has been reached; the bulk of the muscle appears to be higher than usual on the leg, and the length of the tendo Achillis to be increased. In the most severe grade of distortion, very slight motion is permitted at the ankle-joint, in consequence of the position of the astragalus and the tense retraction of the extensor muscles. Thus, eventually, the purposes of the articulation are no longer fulfilled the articular cartilages on the anterior and lateral surfaces of the astragalus, and on the superior portion of the head of the astragalus, become thin and irregular, or they are removed, exposing the osseous surfaces; whilst the synovial membranes are softened, the ligaments lose their elasticity, and the muscles undergo fatty degeneration.

TALIPES CALCANEUS.-Non-congenital calcaneus generally occurs as a paralytic affection: the heel drops, from paralysis of the muscles of the calf of the leg. The anterior portion of the foot is slightly raised from the ground, and the heel only is in contact with the ground. (See fig. 23).

Fig. 23.

When, however, it is induced by accident or affection of the anterior muscles of the leg, the distortion simulates more closely the congenital distortion. M. extensor longus digitorum, extensor proprius pollicis, tibialis anticus, and peroneus tertius are retracted, slightly or forcibly, to raise the anterior portion of the foot and depress the heel; the tendo Achillis is tense, and the calf of the leg is less wasted than in the first-mentioned variety.

After some continuance of distortion, the lateral tibiotarsal ligaments become extended; and the muscles in the sole of the foot, as well as the plantar fascia, become retracted, and tend still further to draw the heel downwards and forwards.

TALIPES VARUS. This, as every other form of noncongenital distortion, differs materially from congenital distortion, so that at a glance it may be asserted posi

tively that the affection is not congenital. (See figs. 24 and 25.)

Fig. 24.

The foot is seldom as much inverted as in the third degree of congenital varus, and the distortion has not the same solid character as in the congenital affection, but the foot admits of more motion. For the most part, the dorsum of the fifth toe rests on the ground, the muscles in the sole of the foot are retracted, the heel is slightly raised, and the great toe is extended. The act of walking is both slow and painful, on account of the imperfect manner in which the foot is planted on the ground, and the consequent want of solid support; it is painful also because the callosity on the outer side of the foot is very imperfectly developed.

On the outer side of the foot and ankle the ligaments

become considerably extended; and they are somewhat contracted on the inner side. The plantar fascia is generally, also, contracted.

In non-congenital distortions, and especially varus, the diminished vitality of the limb is favorable to inflammation and ulceration: troublesome sores are frequently found, and pressure is ill borne.

The adductor muscles of the foot are occasionally alone retracted; but generally the extensors of the foot are likewise affected. In the worst forms of non-congenital varus the foot is so turned round that the dorsal surface is in contact with the ground and the sole uppermost : this is, however, rare, and only takes place after long-continued use of the distorted

limb.

Fig. 25.

TALIPES VALGUS.-This very painful and common affection commences with a sense of weakness beneath the arch of the foot, which is noticed especially in walking. In the commencement of the affection, when the foot is raised from the ground, no deviation from the normal condition may be observable in its shape, but when the weight of the body is

borne on the foot, as in walking, the inner malleolus is seen to project abnormally, and to be in more than ordinary close proximity to the ground. Gradually and slowly the plantar arch sinks; the plantar ligaments become lengthened, the abductor muscles of the foot shortened, the foot slightly everted, and the motions of the ankle joint painful and impaired. (See fig. 26.)

Fig. 26.

At length, the arch of the foot is destroyed, and the sole, in its entire length, rests on the ground; pain is especially referred to the position of the scaphoid bone, but the act of walking is less painful than before the arch of the foot was destroyed. The foot itself is slightly lengthened, through destruction of its arch, the dorsum is flattened, the outer edge of the foot is slightly raised (see fig. 27); progression is effected slowly and with lameness, and with very slight motion at the tibio-tarsal joint. It is comparatively rare, however, that this affection proceeds to the extent now described; for the pain occasioned by extension