Muscles of the Lower Extremity. 



191 



257. The External Muscles of the Hip. 



M. pyriformis arises within the pelvis from the anterior surface of the 

 sacrum and from the lower portion of the Symphisis sacro-iliaca; it passes through 

 the great sacro-sciatic foramen and is inserted into the upper border of the great 

 trochanter. (Rotator outwards of the thigh.) 



M, obturator interims arises within the pelvis from the border of the 

 obturator foramen and from the inner surface of the obturator mem- 

 brane; it passes trough the lesser sacro-sciatic foramen and receives the attach- 

 ment of the Musculi gemelli, of which the superior arises from the spine of the 

 ischium and the inferior from the tuberosity of the ischium ; these muscles are 

 inserted into the Fossa troclianterica. (Rotators outwards of the thigh.) 



M. quadratus ftmoris arises from the tuberosity of the ischium, and is 

 inserted into the the Linea quadrati on the posterior surface of the femur below 

 the great trochanter. (Rotator outwards of the thigh.) 



M. obturator externus (Fig. 260) arises from the inner and inferior margin 

 of the obturator foramen, and is inserted into the Fossa trochanterica. 

 (Rotator outwards of the thigh.) 



