CHAPTER II. 



INDUSTRIAL LABOUR AND LOCOMOTION. 

 (Continued.) 



272. The Work of the Muscles in Walking. The data for the 

 following calculations of the amount of work done by the muscles 

 during each pace have been taken from the experimental results 

 obtained by Marey and Braune and Fischer. 



We have, first of all, a vertical rise of the body of 0-04 m., 

 followed by a corresponding fall under restraint (we know that, 

 as far as energy is concerned, the one is 52% of the other). Hence 

 in the case of an adult weighing 65 kg. the corresponding mus- 

 cular work done is : 



1 52 



T x = 65 X 0-04 X T = 3-952 kgm. 

 100 



The oscillation of the lower limb produces work to the amount 

 of 



as I = 0-146 ( 267) and 



co = ^ (see 269). 

 The result will be : 



1 Io>2 = \ x 0-146 X = 0-370 kgm. 



Taking the restraint into account, 



In the third place, the general centre of gravity is subjected 

 to a variation of vis viva in its translation : 

 diagramatically, the speed is a minimum at 

 the summit of the trajectory OCO' (fig. 

 o, m ?78 Q- 255), and it varies by about. 0-60 m. accord- 

 j.' (0 255 ing to experimental observations. 



Therefore : 



%mv* = %x ~ X 0^60 2 = 1-192 kgm. 



To include in this evaluation the work of restraint done by the 

 muscles, we have : 



T 3 = 1-192 X = 1-812 kgm. 



