MYOLOGY. 77 



Action. Adductor, extensor and external rotator of thigh. 

 Nerve. Obturator. 



QUADRATUS FEMORIS. 



Origin. Tuber ischii. 



Insertion. Posterior surface of femur, below trochanter. 



Action. Extensor and adductor of femur. 



Nerve. Great sciatic. 



EXTERNAL OBTURATOR. 



Origin. Below margin of obturator foramen. 

 Insertion. Trochanterian fossa. 

 Action. Adductor and external rotator. 

 Nerve. Obturator. 



INTERNAL OBTURATOR. 



Origin. Above margin of obturator foramen. 

 Insertion. Trochanterian fossa. 

 Action. Abductor and external rotator. 

 Nerve. Great sciatic. 



GEMELLI. 



Origin. Above and below tendon of obturator internus, from 

 ischium. 



Insertion. Into tendon of internal obturator. 

 Action. Like preceding. 

 Nerve. Great sciatic. 



ANTERIOR EXTENSOR OF PHALANGES. 



Origin. Digital fossa above external condyle of femur. 



Insertion. Capsular ligament of metatarso-phalangeal articu- 

 lation, anterior surfaces of first two phalanges, and pyramidal 

 eminence of os pedis. 



Action. Extends digit. 



Nerve. External popliteal. - 



LATERAL EXTENSOR OF PHALANGES. 



Origin. External femoro-tibial ligament and whole extent of 

 fibula. 



Insertion. Terminates in tendon of anterior extensor. 

 Action. As preceding. 

 Nerve. External popliteal. 



