244 MYOLOGY. 



Origin. — From about the lower third of the anterior surface 

 of the femur. 



Insertion. — To the upper surface of the patella, and the 

 capsular ligament of the joint. 



Relation. — Anteriorly with the rectus ; posteriorly with the 

 femur ; laterally with the vasti. 



Action. — To assist the vasti, and tense the capsular ligament. 



Posterior Femoral Region. 

 This region contains two muscles, a large superficial one, and 

 a small one deeply situated ; they are as follows : — 

 Biceps rotator tibialis. 

 Ischio-femoralis. 



BICEPS ROTATOR TIBIALIS. 



[Semitendinosics — Ischio-tibialis Posticus.) 



(Pl. IL 61 ; Fig. 84. e. e.) 



Situated behind the triceps abductor, and curved like it, with 

 the convexity behind, this muscle is long, cylindrical, and bifid 

 above, consisting of pale, fleshy fibres, divided by a strong 

 aponeurosis. 



Origin. — By one head, from the spine of the sacrum, and 

 the sacro-sciatic ligament, in common with the triceps abductor ; 

 the other, which is considerably shorter, comes from the ischial 

 tuberosity. 



Insertion. — To the supero-internal part and anterior crest of 

 the tibia, its aponeurosis blending with the tibial fascia and 

 the periosteum. 



Relation. — Superiorly and posteriorly it is covered by the 

 gluteal fascia, and its sacral portion partly covers the triceps 

 abductor, being related with it and the sciatic nerves anteriorly ; 

 externally with the abductor magnus. 



Action. — To extend the femur, flex and rotate the leg out- 

 wards, and tense the tibial fascia. 



ISCHIO-FEMORALIS. 



(Quadratits Femoris.) 



(Fig. 83. e.) 



Situated behind the femur, between the adductor and abductor 

 muscles. This muscle consists of a flattened band, running down- 

 wards and outwards. 



