268 



THE MUSCLES AND FASCIAE OF THE LOWER LIMB. 



THE MUSCLES AND FASCIAE OF THE FOOT. 



. The fascia of the dorsum of the foot is reduced to a thin 

 membrane prolonged from the anterior annular ligament over the extensor tendons. 

 Beneath it, deeper layers of fascia are placed over the short extensor of the toes and 

 the interosseous muscles. 



The superficial fascia of the sole resembles that of the palm of the hand. It 

 forms a thick cushion, especially over the bony prominences, and consists mainly of 

 small lobules of fatty tissue bound down by numerous fibrous bands which pass 

 vertically from the skin to the deep fascia. Small bursse are often formed over the 

 heel and the heads of the first and fifth metatarsal bones. 



The deep fascia of the sole, or plantar fascia, consists of a central and two 

 lateral portions, which are marked off from each other by superficial grooves, 



Fig. 260. SUPERFICIAL MUSCLES AND TENDONS ON THE DORSUM or 



THE FOOT AND LOWER PART OF THE FRONT OF THE LEO. 



(After Bourgery.) | 



a, tibia ; I, fibula ; c, navicular bone ; d, internal cuneiform 

 bone ; 1, 1', tibialis anticus ; 2, extensor proprius hallucis ; 2', its 

 expansion on the dorsum of the great toe : 3, extensor communis 

 cligitorum dividing into its four tendons for the toes ; 3', its ex- 

 pansion, and 3", final insertion (upon the second toe) ; 4, peroneus 

 tertius ; 4', its insertion on the base of the fifth metatarsal bone ; 

 5, soleus ; 6, peroneus brevis ; 7, extensor brevis digitorum ; 7', 7", 

 placed on the transverse band of aponeurosis, marks the first and 

 fourth tendons of the extensor brevis muscle ; 8, 9, part of the 

 anterior annular ligament ; 10, 11, a transverse band of the dorsal 

 fascia of the foot. 



indicating the position of intermuscular septa. The 

 inner portion, thinner and looser than the others, invests 

 the abductor hallucis, and is continuous round the 

 inner border of the foot with the dorsal fascia and 

 with the lower fibres of the internal annular liga- 

 ment. The outer part covers the abductor minimi 

 digiti, is much stronger, and forms a particularly 

 thick band between the outer tubercle of the os calcis 

 and the tuberosity of the fifth metatarsal bone. It is 

 continuous round the outer border of the foot with 

 the dorsal fascia, and sends a thin prolongation for- 

 wards over the insertion of the abductor and the short 

 flexor muscles of the little toe. The central portion is 

 exceedingly strong, and is composed of dense white 



glistening fibres, the greater number of which run longitudinally from the os calcis 

 to the roots of the toes. It is narrow and thick behind, where it is attached to the 

 inner tubercle of the os calcis, immediately below the origin of the flexor brevis 

 digitorum, with which muscle it is closely connected. It becomes broader and 

 thinner as it extends forwards, and near the heads of the metatarsal bones it 

 divides into five processes, one passing to each of the toes. In the intervals between 

 the processes a thin membrane composed of transverse fibres covers the lumbricales 

 muscles and the digital nerves. The arrangement of the processes is identical with 

 that of the corresponding part of the palmar fascia, fibres being sent to the digital 

 sheaths, superficial transverse ligament and skin, as well as deep processes on each 

 side of the flexor tendons to the transverse metatarsal ligament. 



The two intermuscular septa, which are given off between the middle and lateral 



