THE FASCIA AND MUSCLES OF THE LEG AND FOOT. 423 



peroneal retinaculum binds them down separately on the lateral surfaces of the 

 calcaneus. 



The ligamentum transversum cruris (O.T. anterior annular ligament, 

 upper band), broad and undefined at its proximal and distal borders, stretches 

 across the front of the ankle between the two malleoli. This band binds down, to 

 the distal end of the tibia, the tendons of the tibialis anterior and extensor 

 muscles of the toes. One mucous sheath is found deep to it, surrounding the 

 tendon of the tibialis anterior. 



Ligamentum Cruciatum Cruris. On the dorsum of the foot, where the 

 general covering of deep fascia is much thinner, a special well-defined band, named 

 the ligamentum cruciatum cruris (O.T. anterior annular ligament, lower band), 

 stretches over the extensor tendons. It has an attachment laterally to the lateral 

 border of the dorsal surface of the calcaneus. It divides into two bands as it 

 passes medially over the dorsum of the foot a proximal part, which joins the 

 Kg. transversum cruris and is attached to the medial malleolus, and a distal part, 

 which passes across the dorsum of the foot, and joins the fascia of the sole at its 

 medial border. 

 Deep to this liga- 

 ment are three 

 special compart- 

 ments with separ- 

 ate mucous sheaths, 

 one for the tibialis 

 anterior tendon, a 

 second for that of 

 the extensor hal- 

 lucis longus, and a 

 third for the ex- 

 tensor digitorum 

 longus and per- 

 onseus tertius ten- 

 dons. There are 

 occasionally other 

 additional bands 

 of the deep fascia 

 passing, like the 

 straps of a sandal, 

 across the dorsum 

 of the foot. 



The plantar 



aponeurosis is of great importance. In the centre of the sole it forms a thick 

 triangular band, attached posteriorly to the tuberosity of the calcaneus. It 

 spreads out anteriorly and separates intone slips, which are directed forwards to 

 the bases of the toes. These slips as they separate are joined together by ill-defined 

 bands of transverse fibres, which constitute the superficial transverse metatarsal 

 ligament (fasciculi transversi aponeurosis plantse). The slip for each toe joins the 

 tissue of the web of the toe and is continuous with the digital sheath. It splits 

 to form a band of fibres directed forwards on each side of the toe to be attached to 

 the sides of the metatarso-phalangeal articulation and the base of the first phalanx. 



This central portion of the plantar aponeurosis assists in preserving the arch of 

 the foot, by drawing the toes and the calcaneus together. 



On each side it is continuous with a much thinner layer, which covers the lateral 

 and medial muscles of the sole and joins the fascia of the dorsum of the foot at 

 each border. It also gives rise to intermuscular septa, which pass deeply on each 

 side of the flexor digitorum brevis, enclosing that muscle in a separate sheath, and 

 giving investments on either side to the abductor muscles of the great and little 

 toes. At the lateral border of the foot the calcaneo-metatarsal ligament, a thickened 

 band of the fascia, connects the tuberosity of the calcaneus with the base of the 

 fifth metatarsal bone. 



EXTENSOR HALLUCIS LONGUS 

 Deep peroneal nerve and 

 dorsalis pedis artery 

 EXTENSOR DIGITORUM LONGU 



PERON^US TERTIU 



Fibula 



Interosseous talo- 

 calcaneal ligament 



Calcaneus 



PERON^EUS BREVIS 



Peroneal retinaculum 



PERON^US LONGUS 



ABDUCTOR DIGITI QUINTI 

 Plantar aponeurosi 



.Lig. transversum cruris. 



fes TIBIALIS ANTERIOR 



Tibia 



Talus 



TIBIALIS POSTERIOR 



Ligamentum 

 laciniatum 



/_FLEXOR DIGITORUM 



LONGUS 



Medial plantar artery 

 Medial plantar nerve 

 FLEXOR HALLUCIS LONGUS 



ABDUCTOR HALLUCIS 



Lateral plantar nerve 

 Lateral plantar artery 

 FLEXOR DIGITORUM BREVIS 



QUADRATUS PLANTS 



FIG. 1 377. FRONTAL SECTION THROUGH THE LEFT ANKLE-JOINT, TALUS, 

 AND CALCANEUS. 



