FOOT AND FOREARM AS LEVERS 



63 



for the maintenance of the foot as an arched lever. 

 Some of these are shown in fig. 16. The foot, then, is 

 a lever of a very remarkable kind ; all the time we stand 

 or walk, its rigidity, its power to serve as a lever, has to 

 be maintained by an elaborate battery of muscular engines 

 all kept constantly at work. No wonder our feet and 

 legs become tired when we have to stand a great deal. 

 Some of these engines, the larger ones, are kept in the 

 leg, but their tendons or piston cords descend below the 



Hind supportina 

 muscle 



ron 



n 



uscle 



Fig. 16. — The arch of the foot from the inner side, showing some of the 

 muscles which maintain it. 



ankle-joint to be fixed to various parts of the arch, and 

 thus help to keep it up (fig. 16). Within the sole of 

 the foot has been placed an installation of seventeen 

 small engines, all of them springing into action when 

 we stand up, thus helping to maintain the foot as a rigid 

 yet flexible lever. 



We have already seen why our muscles are so easily 

 exhausted when we stand stock-still ; they then get no 

 rest at all. Now, it sometimes happens in people who 

 have to stand for long periods at a stretch that these 

 muscular engines which maintain the arch are overtaxed ; 

 the arch of the foot gives way. The foot becomes flat 



