ANTERIOR TIBIAL GROUP. 245 



Origin. — From the inferior surface of the ischium, in front of 

 the tuberosity. 



Insertion. — To a linear imprint on the posterior surface of the 

 femur, just below the level of the trochanter intemus. 



Relation. — Anteriorly with the femur and obturator externus ; 

 posteriorly and externally with the adductor magnus ; internally 

 with the gemellus posticus, and the sciatic nerves. 



Action. — To extend and adduct the femur, but not, in the 

 horse, to rotate it. 



Tibial Region. 



This region corresponds to the antibrachial region of the 

 anterior limb, and, like the latter, contains chiefly flexor and 

 extensor muscles. The strong tibial fascia invests the region, 

 and is attached to the tibial crest, and to the summit of the 

 calcaneum, being tensed by the gracilis and other muscles. 

 The muscles of this region cover the tibia and fibula, except on 

 the inner side of the former, and they consist of an anterior and 

 a posterior group ; but as the flexor side of the tarsal joint is 

 anterior, and, in the joints below, posterior, we find flexor and 

 extensor muscles both before and behind. In the anterior limb 

 it is not so, the carpus and the joints beloAV all flexing in the 

 same direction. 



Anterior Tibial Group. 



We subdivide this group into the flexors and extensors; there 

 are two of the latter and only one of the former. 



Flexor. Extensors. 



Flexor metatarsi. I Extensor pedis. 



I Peroneus. 



FLEXOR METATARSL 



(Tibio-premetatarseus.) 



(Fig. 85. a.) 



This muscle is situated on the antero-external aspect of the leg, 

 and consists of two distinct parts, one fleshy, the other tendinous. 

 The tendinous portion appears as a very strong fibrous cord, situ- 

 ated in front of the fleshy portion, and running the whole length 

 of the muscle. The fleshy portion is coniform, thick above, and 

 thinner below. 



