THE INTERNAL FEMORAL REGION. 511 



Gluteus maximus in f apporting the knee in the extended position. TheSartorius 

 flexes the leg upon ihe thigh, and. continuing to act, flexes the thigh upon the 

 pelvis : it next rotates the thigh outward. It was formerly supposed to adduct the 

 thigh, so as to cross one leg over the other, and hence received its name of Sartorius. 

 or tailor's muscle (sartor, a tailor), because it was supposed to assist in crossing the 

 k'^s in the squatting position. When the knee is bent the Sartorius assists the 

 Semitendinosus, Semimembranosus, and Popliteus in rotating the tibia inward. 

 Taking its fixed point from the leg, it flexes the pelvis upon the thigh, and, if one 

 muscle acts, assists in rotating the pelvis. The Quadriceps extensor extends the 

 leg upon the thigh. Taking its fixed point from the leg, as in standing, this muscle 

 will act upon the femur, supporting it perpendicularly upon the head of the tibia, 

 and thus maintaining the entire weight of the body, or in the stooping position it 

 will straighten the knee, and therefore assist the trunk in rising into the erect 

 position. The Rectus muscle assists the Psoas and Iliacus in supporting the pel- 

 vis and trunk upon the femur or in bending it forward. 



Surgical Anatomy. A few fibres of the Rectus muscle are liable to be ruptured from 

 severe strain. This accident is especially liable to occur during the games of football and cricket, 

 and is sometimes known as "cricket thigh. " The patient experiences a sudden pain in the part, 

 as if he had been struck, and the Rectus muscle stands out and is felt to be tense and rigid. The 

 accident is often followed by considerable swelling from inflammatory effusion. Occasionally the 

 Quadriceps extensor may be torn away from its insertion into the patella, or the tendon of the 

 patella may be ruptured about an inch above the bone. This accident is caused in the same 

 manner as fracture of the patella by muscular action is produced viz. by a violent muscular 

 effort to prevent falling whilst the knee is in a position of semiflexion. A distinct gap can be 

 felt above the patella, and, owing to the retraction of the muscular fibres, union may fail to take 

 place. 



Internal Femoral Region. 



Gracilis. Adductor longus. 



Pectineus. Adductor brevis. 



Adductor magnus. 



Dissection. These muscles are at once exposed by removing the fascia from the fore part 

 and inner side of the thigh. The limb should be abducted, so as to render the muscles tense 

 and easier of dissection. 



The Gracilis (Figs. 326. 329) is the most superficial muscle on the inner side 

 of the thigh. It is thin and flattened, broad above, narrow and tapering below. 

 It arises by a thin aponeurosis, between two and three inches in breadth, from the 

 lower half of the margin of the syinphysis and the inner margin of the descending 

 ramus of the os pubis. The fibres pass vertically downward, and terminate in a 

 rounded tendon which passes behind the internal condyle of the femur, and, 

 curving round the inner tuberosity o the tibia, becomes flattened, and is inserted 

 into the upper part of the inner surface of the shaft of the tibia, below the tuber- 

 osity. The tendon of this muscle is situated immediately above that of the 

 Semitendinosus. and is surrounded by the tendon of the Sartorius, with which it is 

 in part blended. As it passes across the internal lateral ligament of the knee-joint 

 it is separated from it by a synovial bursa common to it and the Semitendinosus 

 muscle. 



Relations. By its superficial surface, with the fascia lata and the Sartorius 

 below : the internal saphenous vein crosses it obliquely near its lower part, lying 

 superficial to the fascia lata ; the internal saphenous nerve emerges between its 

 tendon and that of the Sartorius ; by its deep surface, with the Adductor brevis and 

 the Adductor magnus and the internal lateral ligament of the knee-joint. 



The Pectineus (Fig. 326 ) is a flat, quadrangular muscle situated at the anterior 

 part of the upper and inner aspect of the thigh. It arises from the linea ilio- 

 pectinea. from the surface of the bone in front of it between the pectineal eminence 

 and spine of the os pubis, and from the fascia covering the anterior surface of the 

 muscle : the fibres pass downward, backward, and outward, to be inserted into a 

 rough line leading from the lesser trochanter to the linea aspera. 



Relations. By it.- >mi. ,-ior surface, with the pubic portion of the fascia lata. 



