54 THE POCKET ANATOMY 



of upper edge of great trochanter(x) (ist and and Sacral). 

 [Rotates the thigh outwards.] Goes through great sacro-sciatic 

 foramen. 



Obturator interims : posterior surfaces of pubic arch, obtu- 

 rator membrane, and ischium behind ; from great sciatic 

 notch, fascia(F) front of upper border of great trochanter 

 with the gemelli(T) (Sacral plexus). [External rotator of 

 thigh.] Passes through small sacro-sciatic foramen. 



The obturator membrane closes the thyroid foramen, except 

 at the upper and outer part, where a canal is left for the 

 obturator vessels and nerve. 



Gemellus superior : outer surface of ischial spine(F) 

 superior border of great trochanter anterior to the pyriformis 

 with obturator internus(x) (Sacral plexus). [Rotates thigh 

 outwards.] 



Gemellus inferior : superior and outer border of tuber ischii 

 (F) superior border of great trochanter with obturator in- 

 ternus(T) (Sacral plexus). [Rotates thigh outwards.] 



Obturator externus : anterior half of outer surface of obtu- 

 rator membrane, rami of pubis and ischium(F) digital fossa 

 at root of great trochanter(x) (Posterior division of obturator). 

 [Rotates thigh outwards.] 



Quadratus femoris : external border of tuber ischii(F) 

 tubercle on posterior inter-trochanteric ridge, and downwards 

 as far as insertion of adductor magnus(p) (Sacral plexus). 

 [External rotator and adductor of thigh.] 



POSTERIOR FEMORAL REGION. 



Biceps : Long head. Lower and inner impression on tuber 

 ischii, and great sacro-sciatic ligament(T). Short head. Outer 

 lip of linea aspera in the lower half, upper part of line to ex- 

 ternal condyle, external inter-muscular septum(F) by two 

 slips embracing the external lateral ligament upon the outer 

 side of head of fibula(T) (Great sciatic). [Flexes knee and 

 extends thigh, rotates leg outwards.] Forms outer hamstring. 



Semi-tendinosus : lower and inner impression on tuber ischii 

 with the biceps(x), tendon of biceps(p) upper part of internal 

 surface of tibia, under cover of the sartorius(x) (Great sciatic). 

 [Extends thigh, flexes knee, and rotates leg inwards.] 



Semi-membranosus : upper and outer impression on the 

 tuber ischii(x) (i) hinder part of lower lip of groove on 

 internal tibial tuberosity(x) beneath internal lateral ligament 

 (2) forms principal part of posterior ligament of knee 

 (3) into fascia over popliteus (Great sciatic). [Extends thigh, 

 flexes knee, and rotates leg inwards.] 



