82 ANATOMY AND PHYSIOLOGY FOR NURSES 



ischium. Insertion, into the posterior inter trochanteric 

 line. Action, abducts the thigh and rotates it outward. 

 Nerve, branch of the sacral plexus. 



The muscles of the posterior femoral region are 

 the biceps, the semitendinosus, and the semimembrano- 

 sus. 



The biceps is a large muscle situated on the outer part 

 of the thigh. It arises by two heads, the long from the 

 tuberosity of the ischium and the short from the linea 

 aspera. Insertion, head of the fibula, the tendon thereof 

 splitting, one band embracing the lateral ligament and the 

 other extending to the outer tuberosity of the tibia ; this 

 muscle is called the outer hamstring. Action, extends the 

 hip, flexes the leg, after which it rotates it outward. 

 Nerve, great sciatic. 



The semitendinosus is situated on the inner side of the 

 thigh; this is a remarkable muscle, as it is provided with 

 a very extensive tendon. It arises from the tuberosity 

 of the ischium and is associated with the biceps; it con- 

 tinues downward, the muscular belly becoming ten- 

 dinous a little below the middle of the thigh. It 

 is inserted into the upper and inner part of the tibia. 

 Action, extends the hip, flexes the leg on the thigh, and 

 rotates it inward. Nerve, great sciatic. 



The semimembranosus arises from the tuberosity of the 

 ischium. It is inserted into the inner and back part of the 

 tuberosity of the tibia. Action, flexes the leg on the thigh 

 and rotates it inward. Nerve, great sciatic. 



Muscles of the Leg. Having studied the muscles of 

 the thigh and hip, those of the leg and foot will now be 

 considered. Of these, only the most important, and es- 

 pecially the most superficial, will be described. 



There are thirteen muscles in the leg; these are as 

 follows : 



The tibialis anticus, extensor longus digitorum, ex- 



