342 HEALTH AND DISEASE 



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

 Action. To adduct the limb and rotate it outwards. 



Adductor Magnus. A long thick muscle placed on 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. 



Insertion. 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) on 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. 



Insertion. 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. 



