FASCIAE OF THE FOOT. 97 



the last phalanges of the lesser toes by 4 tendons which FIG. 51. 



perforate the tendons of the flexor brevis digitoriim. 

 Action, to flex the phalanges and extend the foot. Nerve, 

 posterior tibial. 



Tibialis Posti'cus, 8 by two processes between which pass the 

 anterior tibial vessels, from the upper one-half of shaft of 

 the tibia posteriorly, the upper two-thirds of the shaft of the 

 fibula internally, the interosseous membrane, deep fascia, 

 and intermuscular septa, passes behind the inner malle- 

 olus in a groove 13 with the long flexor, into the tuberosity 

 of the scaphoid and internal cuneiform bones. Action, to 

 extend the tarsus, and invert the foot. Nerve, posterior 

 tibial. 



Peroneus Longus, 10 from the head of the fibula and the 

 upper two-thirds of its shaft externally, the deep fascia, 

 and intermuscular septa, passes behind the outer malleo- 

 lus in a groove with the peroneus brevis, through a groove 

 in the cuboid bone, to the outer side of the base of the 

 1st metatarsal bone. Action, to extend and evert the foot. 

 Nerve, musculo-cutaneous. 



Peroneus Brevis, 11 from the middle one-third of the shaft 

 of the fibula externally, and the intermuscular septa, 

 passes behind the external maFeolus in a groove with 

 the long peroneal, into the dorsum of the base of the 5th 

 metatarsal bone. Action, to extend the foot. Nerve, 

 musculo-cutaneous branch of external popliteal. 



FASCIA OF THE FOOT. 



ANTERIOR ANNULAR LIGAMENT, consists of vertical and horizontal portions, 

 is attached to the lower ends of the fibula and tibia, the os calcis and the 

 plantar fascia. It contains 5 sheaths lined by synovial membranes for the 

 tendons of the extensor muscles, that of the extensor proprius pollicis pass- 

 ing beneath it, as also the anterior tibial vessels and nerve. 



INTERNAL ANNULAR LIGAMENT, from the inner malleolus to the os calcis, 

 converting 3 bony grooves into canals lined by synovial membranes for the 

 flexor tendons and the posterior tibial vessels and nerve. 



EXTERNAL ANNULAR LIGAMENT, from the outer malleolus to the os calcis, 

 binding down the peronei tendons in one synovial sac. 



PLANTAR FASCIA, the densest in the body, divided into a central and two 

 lateral portions, and attached to the inner tuberosity of the os calcis, divides 

 into 5 processes, I for each toe, and several intermuscular septa. 

 9 G 



