328 Anatomy Applied to Medicine and Suigery. 



of the gracilis. Actions. To extend the hip and flex the 

 knee, and, acting from below, to assist in raising the body 

 from the stooping position. 



Semi-membranosus, from the anterior and outer facet 

 of the ischial tuberosity ; into the inner and back part of 

 internal tuberosity of the tibia; into the posterior liga- 

 ment of the knee, and into the fascia over the popliteus 

 muscle. A ction. To extend the hip and flex the knee, and, 

 when acting from below, to assist in raising the body 

 from a stooping position. The peculiar arrangement of 

 this penniform muscle, whereby the upper or proximal 

 end is flattened, permits the free action of the biceps mus- 

 cle which crosses it above, for, if it were not thus flatten- 

 ed, the resultant increased thickness of the muscle, when 

 acting, would interfere with the contraction of the biceps. 



Anterior Muscles. Rectus fenwris, from the an- 

 terior inferior spine of ilium by one head, and from the up- 

 per surface of the rim of the acetabulum by the other; 

 into the front of the upper border of the patella. Action. 

 To extend the leg and assist in flexing the thigh. 



Vastus externus, from the anterior intertrochanteric 

 line, from the front of the great trochanter, and lower 

 border of same, and from the outer lip of the linea aspera ; 

 into the outer half of the upper border of patella and into 

 the upper third of its outer border. Action. The same 

 as the two following muscles. 



Vastus internus and crureus, from the lower part of 

 the line from the inner side of the neck to the linea aspera, 

 from the inner lip of the linea aspera and the line leading 

 from this to the internal condyle, from the whole of the 

 external, internal and anterior surfaces of the shaft of 

 femur, to within the lower fourth of that bone; into the 

 posterior aspect of the upper border of the patella and in- 

 to the upper half of the inner border of that bone. Action. 



