MUSCLES 57 



THE ANTERIOR ANNULAR LIGAMENT consists of two parts. 

 A superior or vertical part, attached to the anterior border of 

 the tibia internally, and to the anterior border of the fibula 

 externally, being continuous above with the fascia of the leg, 

 and divided into two compartments, the internal one for the 

 tibialis anticus tendon, which alone has a synovial sheath, 

 the outer one for the extensor longus digitorum and peroneus 

 tertius tendons. An inferior or horizontal part, which is attached 

 externally to the upper surface of the os calcis, passes 

 inwards across the foot and divides, the upper band being 

 attached to the inner malleolus, the lower to the fascia over 

 the foot. It contains three compartments, with separate 

 synovial sacs, the internal one for the tibialis anticus tendon, 

 the middle one for the extensor proprius hallucis tendon, 

 and the external one for the extensor longus digitorum and 

 peroneus tertius tendons. 



THE INTERNAL ANNULAR LIGAMENT passes between the 

 inner malleolus and the inner margin of the os calcis, being 

 continuous above with the deep fascia, and below with the 

 plantar fascia. It is divided into three compartments. The 

 one next the malleolus transmits the tibialis posticus tendon, 

 the next one the flexor longus digitorum, and the lowest, on 

 the astragalus, the flexor longus hallucis. Between these last 

 two canals the posterior tibial vessels and nerve pass under 

 the ligament. 



THE EXTERNAL ANNULAR LIGAMENT passes from the outer 

 malleolus to the os calcis, binding down the peronei tendons. 



THE PLANTAR FASCIA consists of a central and two lateral 

 parts. 



The inner part covers the abductor hallucis, and is con- 

 tinuous with the dorsal fascia. 



The outer part covers the abductor minimi digiti, and ex- 

 tends from the external tubercle of the os calcis to the base 

 of the 5th metatarsal. 



The central part is attached behind to the internal tubercle 

 of the os calcis, and, extending forwards, splits up into five 

 parts at the heads of the metatarsal bones, one part passing 

 to each of the toes. 



FOOT, DORSAL REGION. 



Extensor brevis digitorum : superior surface of os calcis 

 in front of groove, anterior annular ligament(F) four tendons, 

 inner one to base of ist phalanx of great toe, rest to outer 

 side of tendons of long extensor to 2nd, 3rd, and 4th toes(T) 



