MYOLOGY. 71 
2. MUSCLES OF THE FORE PART AND SIDES OF THE THIGH. These are 
eleven in number. 
Tensor vagine femoris arises from the exterior internal part of the anterior 
superior spinous process and crest of the ilium, and is inserted into a dupli- 
eature of the fascia lata on the outside of the thigh, about three or four inches 
below the great trochanter. Use: to make tense the fascia, to compress 
the vastus externus, to rotate the thigh inwards, and to assist in flexing and 
abducting it. 
Sartorius, or the tailor’s muscle, is the longest muscle in the body. Thin 
and flat, like a ribbon, it is situated obliquely along the anterior and inner 
side of the thigh, arising from the anterior superior spine of the ilium and 
from the notch below that process. It extends obliquely across the thigh to 
its inner side, and descending perpendicularly to the knee, it passes behind 
the condyle of the femur. It then turns forwards and outwards towards the 
inner side of the upper end of the tibia, into which it is inserted below the 
tubercle. Use: to flex the leg on the thigh and the thigh on the pelvis, to 
cross the lower extremities, &c. 
Rectus femoris is a long and flat muscle, placed vertically on the fore part 
of the thigh. It arises by two tendons, one from the anterior inferior spinous 
process of the ilium, the other from the superior and external border of the 
acetabulum. These soon unite into a strong fleshy belly ending in a flat 
tendon, which is inserted into the upper edge of the patella. Use: to extend 
the leg on the thigh and to flex the leg on the pelvis. Its action is greatly 
facilitated by the patella, which enables it to act at greater mechanical 
advantage. ‘This muscle is internally united to three others subjacent to 
it; the four, in fact, form a single quadriceps muscle. Of these the ex- 
ternal is called vastus externus, the middle, crureeus, and the internal, vastus 
internus. 
The vastus externus arises from the root and anterior part of the great 
trochanter, from the outer edge of the linea aspera, and from the oblique 
ridge which leads to the external condyle. It is inserted into the external 
surface of the tendon of the rectus, and into the patella. It extends the 
knee, and rotates the leg outwards. 
Vastus internus arises on the anterior edge of the femur, and is inserted 
into the inner edge of the tendon of the rectus and into the patella. Use: 
to extend the knee and turn the leg a little inwards. 
Crureus, between the two last, arises from the anterior and external part 
of the femur, and is inserted into the upper and anterior edge of the patella. 
It assists the vasti and rectus in extending the leg. 
Gracilis, situated at the inner side of the thigh, beneath the integuments 
and fasciz, arises from the lower half of the symphysis and from the 
inner edge of the descending ramus of the pubes. It is inserted into 
the superior part of the internal surface of the tibia. Use: to abduct 
the leg and thigh, to bend the knee, and turn the leg and foot in- 
wards. 
Pectineus arises from the linea innominata and the convex surface below 
it on the horizontal ramus of the pubes, and is inserted into the rough ridge 
777 
