88 THE HUMAN BODY. 



on the left leg alone. When the right leg completes its step 

 its knee is straightened and the foot thus brought, heel 

 first, on the ground ; while it is swinging forwards the left 

 foot is gradually raised, and at the end of the step its great 

 toe alone is on the ground ; with this a push is given as 

 before with that of the right foot, and the left leg then 

 swings forward to make the next step. Walking may, in 

 fact, be briefly described as the act of continually falling 

 forwards and preventing the completion of the fall by 

 thrusting out a leg to meet the ground in front. 



During each step the body sways a little from side to 

 side, as it is alternately borne by the right and left legs. 

 It also sways up and down a little ; a man standing with 

 his heels together is taller than when one foot is advanced, 

 just as a pair of compasses held erect on its points is high- 

 er when its legs are together than when they straddled 

 apart ; in that period of each step when the advancing 

 trunk is balanced vertically over one leg, the walker's trunk 

 is more elevated than when the front foot also is on the 

 ground. Women, accordingly, often find that a dress 

 which clears the ground when they are standing sweeps 

 the pavement when they walk. 



The length of each step is primarily dependent on the 

 length of the legs, though it can be largely controlled by 

 special muscular effort, as we see in a regiment of soldiers. 

 all of whom have been taught to take the same stride, no 

 matter how their legs vary in length. In natural easy 

 walking, little muscular effort is employed to carry the 

 rear leg forward after it has given its push ; it swings on 



At what part of a step is a man tallest? Give illustrations. 

 What primarily determines the lengti Df a person s step? Can 

 this length be controlled? 



