342 HEALTH AND DISEASE 



Insertion. — Into the middle of the posterior aspect of the femur. 



Action. — To addnct the limb and rotate it outwards. 



Adductor Magnus. — A long thick muscle placed ou the inner part of 

 the thigh. 



Origin. — From the under surface of the ischium and from the tendon of 

 the gracilis. 



Insertion. — By two divisions: (l) Into the posterior surface of the 

 middle third of the femur; (2) into the same bone above the internal 

 condyle. The femoral artery passes between the two insertions. 



Action. — To adduct the limb. 



QuadratUS Femoris. — This is a small flat band lying deep in the 

 substance of the thigh behind. 



Origin. — From the under surface of the ischium in front of the 

 tuberosity. 



Insertio7i. — Passing in a forward and downward direction it becomes 

 inserted into the posterior aspect of the femur, a little below the bony 

 projection (trochanter minor internus) ou the inner side of the bone. 



Action. — To extend the femur on the pelvis and adduct the leg. 



Gemelli. — A small, flat, thin muscle situated behind the last described. 



Origin. — From the external border of the ischium. 



Insertion. — Its tendon joins with those of the obturator internus and 

 pyriformis, and the three together become inserted into the trochanteric 

 fossa (a pit behind the head of the thigh-bone). 

 Action. — To rotate the femur outwards. 



Obturator Externus. — This is a small, thin, flat muscle situated 

 beneath the pelvis. It covers the obturator foramen, and its fibres con- 

 verge outwards, and end in a short flattened tendon. 



Origin. — From the under surface of the pubis and ischium. 



Insei-tion. — Into the trochanteric fossa behind and below the head of 

 the femur. 



Action. — It assists in extending the femur on the pelvis and rotating 

 the hip outwards. 



Obturator Internus. — A small flat muscle situated on the floor of 

 the pelvis, where it is spread over the obturator foramen. 



Origin. — From the inner circumference of the obturator opening. 



Insertion. — By a tendon common to this muscle and the pyriformis to 

 the large depression (trochanteric fossa) on the upper and back part of the 

 femur. 



Action. — It rotates the femur outwards. 



Pyriformis. — A small flat muscle situated within the pelvis. 



Origin. — From the internal surface of the ilium near the hip-joint. 



