424 



THE MUSCULAK SYSTEM. 



The digital sheaths, though smaller, are the same in arrangement as those of 

 the fingers (p. 389). Vaginal ligaments are present in relation to the first and 

 second phalanges. 



THE MUSCLES OF THE LEG AND FOOT. 



The muscles of the leg and foot are divisible into three series : (1) the extensor 



muscles on the front of the leg and 

 dorsuni of the foot ; (2) the peronaei 

 on the lateral aspect of the leg ; and 

 (3) the flexor muscles on the back of 

 the leg and in the sole of the foot. 



Vaginal 

 ligament 



The IVIuscIesonthe Front 

 of the Leg and Dorsum 

 of the Foot. 



The muscles on the front of the 

 leg and dorsum of the foot include 

 two groups: (1) on the front of the 

 leg, the tibialis anterior, long extensors 

 of the toes and peronseus tertius ; and 

 (2) on the dorsum of the foot, the 

 extensor digitorum brevis, and ex- 

 tensor hallucis brevis. 



On the front of the leg the tibialis i 

 anterior and the extensor digitorum 

 longus and peronseus tertius are 

 superficially placed, and conceal the 

 extensor hallucis longus muscle. On 

 the dorsum of the foot the extensor 

 digitorum brevis muscle lies beneath 

 the tendons of the long extensor oi 

 the toes. 



M. Tibialis Anterior. The 

 tibialis anterior arises from the 

 lateral condyle and the proximal 

 two -thirds of the lateral surface of 

 the body of the tibia, from the inter- 

 osseous membrane from the fascia 

 over it, and from an inter muscular 

 septum laterally. The muscle ends 

 in a strong tendon which pass 

 over the dorsum of the foot, to be 

 inserted into a facet on the medial 

 surface of the first cuneiform and 

 the medial side of the base of the 

 first metatarsal bone (Fig. 379, p. 

 425). Its tendon occupies special 

 compartments beneath both liga- 

 mentum transversum and lig. 

 cruciatum cruris, enclosed in a 

 separate, single, mucous sheath. 



The tibio-fascialis anterior is a separated portion of the muscle occasionally present, inserted 

 into the fascia on the dorsum of the foot. 



Nerve-Supply. Deep peroneal nerve (L. 4. 5. S. 1.). 



Actions. The muscle is a dorsi-flexor of the ankle, and (in combination with the tibialis 

 posterior) it invests the foot. 



Calcaueo- 



metatarsal 



band 



FIG. 378. THE LEFT PLANTAK FASCIA. 



