CHAP. VI.] 



THE MUSCLES. 



69 



If we compare the muscles of the 

 shoulder and arm with those of the 

 hip and leg, we shall see that the an- 

 terior muscles of the former corre- 

 spond roughly with the posterior 

 muscles of the latter, the muscles of 

 the hip and leg, however, being 

 larger and coarser in texture than 

 those of the shoulder and arm. 



The glutei, or three gluteal mus- 

 cles, form the chief prominence of 

 the buttocks. They are coarse in 

 texture, and are powerful abductors 

 of the thigh; but the chief action 

 of the largest of these three muscles, 

 the gluteus maximus, is to bring the 

 body into the erect posture when the 

 trunk is bent forwards upon the 

 thigh. It also comes into operation 

 in ascending stairs, in leaping, and 

 in rising from the sitting posture. 



The posterior femoral or hamstring 

 muscles cover the back of the thigh. 

 There are three of these muscles, 

 the biceps, the semitendinosus, 

 and the semimembranosus. The 

 chief of these is the biceps, and is 

 somewhat analogous to the biceps 

 covering the front of the arm. The 

 action of the hamstring muscles is 

 to flex the knee and to extend the 

 hip. 



The anterior femoral muscles are 

 the quadriceps and sartorius. The 

 quadriceps covers the front of the 

 thigh, and is analogous to the triceps 



covering the back of the arm ; it is 



i f ,1 > , FIG. 61. MuBCLtt OF LBG. Su- 



the great extensor of the leg; it PERFICIAL VJKW OF THK CALF. 



also flexes the hip, and antagonizes 22, temio Achiiiis: 21, gastrocne- 



,, ,. ,, , , , . , mius; 18, soleus; 16, peroueal mus- 



the action of the hamstring muscles. cleSt 



