THIGH AND BUTTOCK. 



its margin (a bursa intervening), and unite later in a single 

 tendon. Insertion; facet on inner surface of great trochanter 

 above digital fossa. [371] 



Gemelli (accessory portions of the preceding) . Gemellus su- 

 perior. Origin; gluteal surface of ischial spine; upper part of 

 margin of lesser sciatic notch. Insertion; upper margin and 

 superficial surface of Obturator internus tendon. Gemellus in- 

 ferior. Origin; upper part of gluteal surface of ischial tuber- 

 osity; lower part of margin of lesser sciatic notch. Insertion; 

 lower margin and superficial aspect of Obturator internus ten- 

 don. [372] 



Quadratus Femoris (of ten fused with Adductor magnus) . 

 Origin; outer margin of ischial tuberosity. Insertion; quad- 

 rate line of femur. A bursa separates it from the small tro- 

 chanter. [372] 



Back of Thigh (Hamstrings). 



Biceps Flexor Cruris. Origin; (long head) great sacro- 

 sciatic ligament and lower and inner facet on ischial tuberosity, 

 in common with Semitendinosus ; (short head) whole of linea 

 aspera and upper two- thirds of external supra-condyloid ridge ; 

 corresponding extent of external mtermuscular septum. 

 Course; the long head soon leaves the Semitendinosus, descends 

 to the lower third of the thigh, and ends in a tendon which is 

 joined by the short head. Insertion; head of fibula, by a ten- 

 don which is bisected by the external lateral ligament of the 

 knee ; popliteal fascia along its posterior border, by transverse 

 aponeurotic fibres from the tendon. [372] 



Semitendinosus. Origin; lower and inner facet on ischial 

 tuberosity, in common with long head of Biceps. Course ; in the 

 mid-thigh it develops in a tendon which descends on the inner 

 side of the knee, spreads out, and becomes membranous. In- 

 sertion; inner side of shaft of tibia, just below the internal tu- 

 berosity, below the Gracilis and behind the Sartorius. A bursa 



[277] 



