MUSCLES EMPLOYED IN RISING FROM A SEAT. 401 



The mode of projecting the foot requires no explanation; 

 but the manner of bringing it to the ground, when thus ad- 

 vanced ought to be noticed. 



If, after standing with both feet on the same line, we move 

 one foot forwards, suppose the right foot, it cannot be applied 

 flat to the ground, unless we either incline the body forward or 

 move the pelvis on the left thigh, so that the right side may 

 present obliquely forward ; or lower the right side of the pelvis, 

 so that it may be nearer the ground. 



When we incline the body forward, and thus bring the right 

 foot to the ground, we perform the second essential process in 

 walking, along with the first : for we move the body over the 

 fore foot. The muscles on the front part of the hind leg, and 

 particularly the tibialis anticus, seem to produce this effect, by 

 bending, or inclining forward, the tibia on the foot. 



When the foot is brought to the ground by a rotation of the 

 pelvis, it is likewise the tibialis anticus, and the muscles on the 

 front of the hind leg, tliat move the body over it, or that begin 

 the motion. 



The gastrocnemius and soleus, and the flexors of the toes, 

 particularly that of the great toe, occasionally co-operate with 

 great effect. By raising the heel, and thus lengthening the 

 hind limb, they push the body forward, and continue its 

 motion in that direction after the effect of the tibialis anticus 

 ceases. The length of the step appears, therefore, to require 

 this elevation of the heel, and depression of the toes ; but it 

 should be observed, that when we take long steps, we also turn 

 the pelvis partly round, presenting the side obliquely forward ; 

 and in this manner increase the anterior projection of the front leg. 



Although the action of the gastrocnemius, &ic., seems neces- 

 sary to walking with long steps, we can walk without their 

 operation. This is proved incontestably by the act of walking 

 on the heel : when the gaslrocnemii and the flexors are so far 

 from acting, that they are in a state of extension. In this ope- 

 ration, the principal effort seems to be made by the tibialis 

 anticus, and the muscles on the front of the leg ; and the exten- 

 sor muscles on the front of the thigh. 

 34* 



