276 THE INFERIOR EXTREMITY 



tendon which inclines forwards, distal to the knee, and then 

 expands and is inserted into the proximal part of the medial 

 surface of the tibia, under cover of the tendon of the sartorius, 

 and at a higher level than the insertion of the semi- 

 tendinosus (Fig. 139, p. 322). A mucous bursa separates the 

 expanded tendon of the gracilis from the tibial collateral liga- 

 ment of the knee joint, and is prolonged proximally, so as to 

 intervene between it and the tendon of the sartorius. The 

 gracilis is supplied by the anterior division of the obturator nerve. 

 It adducts the thigh, flexes the knee joint and rotates the 

 leg medially. 



M. Adductor Magnus. The adductor magnus is one of 

 the most powerful muscles of the thigh. It forms a flat, fleshy 

 mass, which springs from the anterior surface of the entire length 

 of the pubic arch of the corresponding side, and from the lower 

 part of the ischial tuberosity (Figs. 128, 129). The fibres 

 which arise from the pubic arch spread out as they approach the 

 posterior aspect of the femur ; the more medial in origin are 

 the more horizontal in direction ; the more lateral in origin 

 are the more oblique in direction. They are inserted into the 

 posterior part of the femur, just medial to the gluteal tuberosity, 

 into the linea aspera, and into a small portion of the proximal 

 part of the medial supracondylar ridge (Figs. 121, 122). The 

 fibres which take origin from the ischial tuberosity descend 

 almost vertically and form the thick medial border of the 

 muscle. In the distal third of the thigh they end in a strong, 

 rounded tendon, which is inserted into the adductor tubercle 

 on the medial condyle of the femur (Figs. 120, 121). This 

 tendon is further attached to the femur by the medial inter- 

 muscular septum which stretches between it and the medial 

 supracondylar line. Close to the linea aspera are the 

 fibrous arches, formed in connection with the insertion of the 

 adductor magnus, for the passage of the perforating arteries, 

 and in series with them is the opening through which 

 the femoral artery enters the popliteal fossa. The opening 

 is a gap between two portions of the muscle, and is situated 

 at the junction of the proximal two-thirds with the distal 

 third of the thigh (Fig. 120). 



The adductor magnus has a double nerve supply. The 

 fibres which spring from the pubic arch are supplied by the 

 posterior branch of the obturator nerve. Those which arise 

 from the ischial tuberosity are supplied by the sciatic nerve. 



