THE ANKLE AND FOOT. 49 



metatarsal bones in front and the external cuneiform and cuboid bones behind, to its 

 termination behind the tuberosity of the fifth metatarsal bone. 



Over the front of the ankle, the tendons of the anterior muscles of the leg are 

 bound down by the anterior annular ligament ; they can be readily distinguished 

 when the joint is flexed, spreading over the dorsum of the foot, and disposed in the 

 following order : the most internal and the largest is the tibialis anticus ; next 

 comes the extensor proprius hallucis, and then the extensor longus digitorum, 

 dividing into its four slips for the smaller toes ; lastly, proceeding from the outer 

 side of the long extensor to the base of the fifth metatarsal bone is the peroneus 

 tertius ; the last named is, however, not unfrequently wanting. The anterior tibial 

 vessels and nerve are placed, opposite the ankle-joint, between the tendons of the 

 extensor proprius hallucis and extensor longus digitorum. Beneath the tendons of 

 the extensor longus digitorum, on the dorsum of the foot, is placed the extensor 

 brevis digitorum, the fleshy belly of which produces a distinct swelling over the 

 tarsal region. The fleshy mass on the inner margin of the foot is formed by the 

 abductor and flexor brevis hallucis muscles ; and that on the outer border by the 

 abductor and flexor brevis minimi digiti. 



In the sole, the tuberosity of the os calcis and the heads of the metatarsal 

 bones are easily felt, but in the intervening region the bones are not to. be 

 distinguished. The individual muscles are also obscured by the thickness of 

 the integument and the manner in which the parts are bound together by the 

 strong plantar fascia. When the arch of the foot is well developed the parts 

 of the sole that rest on the ground in standing are the heel, a strip near the outer 

 border of the foot, the heads of the metatarsal bones, and the ends of the toes. 

 The skin over these parts is thick, hard, and smooth, but in the hollow of the foot 

 it is soft and wrinkled. The sole of the infant is flatter than that of the adult, 

 and is marked by lines similar to those seen in the palm of the hand, but 

 these disappear more or less completely as age advances. 



On the back of the foot, the arch or plexus of veins shows plainly through 

 the skin, and its extremities may be followed into the internal and external 

 saphenous veins respectively. The musculo-cutaneous and external saphenous 

 nerves are not uncommonly visible through the skin. 



The dorsal artery of the foot extends from the centre of the ankle-joint to the 

 back of the first intermetatarsal space, and it may be felt pulsating midway between 

 the tendons of the extensor proprius hallucis and extensor longus digitorum. Just 

 before its ending it is crossed by the innermost slip of the extensor brevis 

 digitorum. The external plantar artery runs from the bifurcation of the posterior 

 tibial (p. 48) obliquely across the sole to within an inch (2'5 cm.) of the tuberosity of 

 the fifth metatarsal bone, and then is directed more transversely inwards to the 

 back of the first interosseous space, where it meets the termination of the dorsal 

 artery. The internal plantar artery is much smaller than the external ; its position 

 may be indicated by a line drawn from the place of bifurcation of the posterior 

 tibial to the under part of the metatarso-phalangeal articulation of the great toe. 



The metatarso-phalangeal articulations are situated about an inch (2'5 cm.) 

 behind the web of the toes. 



