442 THE MUSCLES AND FASCIAE 



that is rarely, if ever, .congenital, is the talipes cqitinits, the heel being- raised by rigidity and con- 

 traction of the Gastrocnemius muscle, and the .pajtLenL.walking upon the ball of the foot. In the 

 taJ&esjtavwi the foot is forcibly adducted and the inner side of the sole raised, sometimes to a 

 right angle with the ground, by the action of the Tibialis anticus and posticus. In the talipes 

 yalgus the outer edge of the foot is raised by the Peronei muscles, and the patient walks on the 

 inner ankle. In the talipes calcanem the toes are raised by the extensor muscles, the heel is 

 depressed, and the patient walks upon it. Other varieties of deformity are met with, as the 

 talipes equino-varm, cquino-valgiis, and calcaneo-valgus, whose names sufficiently indicate their 

 nature. Of these, the talipes equino-varus is the most common congenital form : the heel is 

 raised by the tendo Achillis, the inner border of the foot drawn upward by the Tibialis anticus, 

 the anterior two-thirds twisted inward by the Tibialis posticus, and the arch increased by the 

 contraction of the plantar fascia, so that the patient walks on the middle of the outer border of 

 the foot. Each of these deformities may sometimes be successfully relieved by division of the 

 opposing tendons and fascia : by this means the foot regains its proper position, and the tendons 

 heal by the organization of lymph thrown out between the divided ends. The operation is 

 easily performed by putting the contracted tendon upon the stretch, and dividing it by means 

 of a narrow, sharp-pointed knife inserted beneath it. 



Rupture of a few of the fibres of the Gastrocnemius or rupture of the Plantaris tendon not 

 uncommonly occurs, especially in men somewhat advanced in life, from some sudden exertion, 

 and frequently occurs during the game of lawn tennis, and is hence known as "lawn-tennis leg." 

 The accident is accompanied by a sudden pain, and produces a sensation as if the individual had 

 been struck a violent blow on the part. The tendo Achillis is also sometimes ruptured. It is 

 .stated that John Hunter ruptured his tendo Achillis whilst dancing at the age of forty. 



IV. MUSCLES AND FASCLE OF THE FOOT. 



The fibrous bands, or thickened portions of the fascia of the leg. which bind down the 

 tendons in front of and behind the ankle in their passage to the foot should now be examined ; 

 they are termed the annular ligaments, and are three in number anterior, internal, and 

 external. 



The Anterior Annular Ligament consists of a superior or trans verse portion, which 

 binds down the Extensor tendons as they descend on the front of the tibia and 

 fibula ; and an inferior or Y-shaped portion, which retains them in connection with 

 the tarsus, the two portions being connected by a thin intervening layer of fascia. 

 The transverse portion is attached externally to the lower end of the fibula and in- 

 ternally to the tibia; above it is continuous with the fascia of the leg; it contains 

 only one synovial sheath, for the tendon of the Tibialis anticus ; the other tendons 

 and the anterior ti trial vessels and nerve passing beneath it, but without any dis- 

 tinct synovial sheath. The Y-shaped portion is placed in front of the ankle-joint, 

 the stem of the Y being attached externally to the upper surface of the os calcis, in 

 front of the depression for the interosseous ligament ; it is directed inward, as a 

 double layer, one lamina passing in front, and the other behind, the tendons of the 

 Peroneus tertius and Extensor longus digitorum. At the inner border of the latter 

 tendon these two layers join together, forming a sort of loop or sheath in which the 

 tendons are enclosed, surrounded by a synovial membrane. From the inner ex- 

 tremity of this loop the two limbs of the Y diverge : one passes upward and inward, 

 to be attached to the internal malleolus, passing over the Extensor proprius hallucis 

 and the vessels and nerves, but enclosing the Tibialis anticus and its synovial sheath 

 by a splitting of its fibres. The other limb extends downward and inward to be 

 attached to the inner border of the plantar fascia, and passes over the tendons of 

 the Extensor proprius hallucis and Tibialis anticus and also the vessels and nerves. 

 These two tendons are contained in separate synovial sheaths situated beneath the 

 ligament. 



The Internal Annular Ligament is a strong fibrous band which extends from 

 the inner malleolus above to the internal margin of the os calcis below, converting 

 a series of grooves in this situation into canals for the passage of the tendons of 

 the Flexor muscles and vessels into the sole of the foot. It is continuous by its 

 upper border with the deep fascia of the leg, and by its lower border with the 

 plantar fascia and the fibres of origin of the Abductor hallucis muscle. The four 

 canals which it forms transmit, from within outward, first, the tendon of the Tibi- 

 alis posticus ; second, the tendon of the Flexor longus digitorum ; third, the pos- 



