THE REGION OF THE ANKLE AND FOOT 493 



navicular ligament and the tendinous sling which they form 

 renders additional support. Further the longitudinal arch 

 is strengthened by the plantar aponeurosis and the abductor 

 hallucis, which connect the bases of its two limbs (Fig. 144). 



The principal Transverse Arch is placed at the level of the 

 distal row of the tarsus and the bases of the metatarsal bones. 

 It is maintained by the plantar inter-tarsal and tarso-metatarsal 

 ligaments,, while the tendon of the peronseus longus stretches 

 across the arch like a bow-string and serves to approximate its 

 extremities (Fig. 147). Additional support is obtained from the 

 tendinous sling formed by the crossing of the flexor longus 



Second cuneiform 

 Dorsalis pedis a. 

 First cuneiform I 



Third cuneiform 



Fibrous sheath of peronaeus longus 

 Peronaus longus tendon 



Cuboid 



Abductor 

 digiti quinti 



i Lateral plantar a. 



Abductor hallucis | I | Lateral plantar n. 



Flexor hallucis brevis | Quadratus plantae 



Flexor hallucis longus tendon Flexor digitorum brevis 



Medial plantar a. | Flexor digitorum longus tendon 

 Medial plantar n. 



FIG. 147. Transverse Section through the Foot, to show the Transverse 

 Arch of the Foot and the Peronaeus Longus Tendon. 



digitorum and hallucis tendons, and from the additional slips 

 of insertion of the tibialis posterior (p. 475), which tend to 

 contract the arch. 



Fiat-Foot. Loss of tone in the muscles which support the 

 arches of the foot throws an increased strain upon the supporting 

 ligaments and constitutes the first stage in the development of 

 flat-foot. At this period treatment must be directed to the 

 weakened muscles, or the ligaments will gradually stretch, 

 giving rise to pain and aching over their attachments. In the 

 second stage both arches give way, the longitudinal flattening 

 being the more noticeable. The head of the talus sinks 

 downwards, forwards and medially so as to increase the interval 

 between the navicular tuberosity and the sustentaculum tali ; 



