Muscles of Thigh 453 



front of the iliac piece of the fascia lata, along which it sometimes 

 travels to the iliac crest. 



The sartorius arises from the anterior superior iliac spine, and 

 passes downwards and inwards over the iliacus and rectus, and the 

 anterior crural nerve. It then descends vertically over and between 

 the vastus internus and the adductor longus, covering the superficial 

 femoral vessels, passing over the adductor magnus, gracilis, long 

 saphenous nerve, and the internal lateral ligament of the knee. It is 

 inserted below the inner tuberosity of the tibia, and into the deep 

 fascia of the leg. It is supplied by the middle cutaneous and other 

 branches of anterior crural nerve. Lying in the groove between the 

 vastus and adductors it is the guide to ligation of the femoral artery, 

 both at the apex of Scarpa's triangle and in Hunter's canal. The 

 surgeon looks for its long parallel fibres as soon as he has incised the 

 fascia lata. 



The rectus femoris arises from the anterior inferior spine of the 

 ilium, and from just above the acetabulum ; these heads join in a 

 tendon which soon spreads out into a bipenniform, fleshy mass, which, 

 lying over the deeper part of the quadriceps extensor (crureus and 

 vasti) is inserted with it into the patella. 



Relations. The origin of the muscle is deeply placed, lying upon 

 the capsule of the hip-joint, beneath the gluteus minimus, iliacus and 

 psoas, and the tensor fasciae femoris ; but in the rest of its extent it is 

 beneath the fascia lata. 



When the muscle contracts with excessive energy it may break off 

 the anterior inferior iliac spine, or detach its epiphysis, or it may tear 

 through the lower tendon. If it be acting with the rest of the quadri- 

 ceps the patella may be broken across, or its ligament may be torn 

 through. 



The adductor longus arises by a slender tendon from the front 

 of the angle of the pubes just below the pubic spine and passes 

 downwards, outwards, and backwards to the middle third of the linea 

 aspera. It separates the superficial from the deep femoral vessels ; 

 and, passing to its insertion behind the origin of the vastus internus, 

 it forms the postero-internal boundary of Hunter's canal. Behind it 

 descend the adductors brevis and magnus, and the anterior division 

 of the obturator nerve. Along its outer and inner borders are the 

 pectineus and the gracilis respectively. 



The adductors longus and brevis and the pectineus are powerful 

 external rotators as well as adductors of the thigh ; they are supplied 

 by the obturator nerve, but the gracilis is a pure adductor, and is 

 supplied by the obturator nerve. The pectineus is as much a flexor 

 as an adductor, and is supplied both by the anterior crural and the 

 obturator ; the psoas is simply a flexor, and is therefore supplied by 

 the anterior crural only, or by twigs of the lumbar plexus. 



