CERTAIN MOVEMENTS IN MAX 



1(35 



of the work. Whatever was the number of steps per 

 minute, the value was marked off on the ordinates 

 from below upwards always in the same order. 



1. The value of the work done in moving the lower 

 extremity. 



2. The value of the work done in the vertical oscil- 

 lation of the body. 



3. The work done in accelerating and slowing the 

 horizontal movement of translation. 



45 JO 



JO JS So 65 yo g* 700 JOS' 110 US tiO 12S 150 135 Mo 74S 



Ffg. 109. — Curves of the different elements of the work perf rmed in walking and 

 running, the rate of prep varying from 40 to 145 per minute The scale to the left 

 of the figure indicates the number of kilogrammetres expanded on each step. Eich 

 of the ordinates is composed of three separate elements, representing the value of 

 each of the c .mpo'ent portions of the total work. The lowest element corresponds 

 to the work performed by the oscillations of the leg. The middle (the thick line) 

 represents the venical oscillations of the body. The superior one corresponds to 

 the degree of acceleration and slowing down of the body mass. 



On the curves represented in Fig. 109, the different 

 factors in the work apparently vary in an extraordinary 

 fashion ; but these variations can easily be accounted 

 for by certain considerations from the point of view of 

 kinetics or dynamics.* 



* To quote from a communication made to the Academie des 

 Sciences, by M. Demeny and ourselves, November 9, 18S5 : — 



A. Variations in Work (b-ne in moving the Lower Limbs. — The work 



