360 THE HUMAN MOTOR 



Small muscular movements due to various other oscillations 

 of the trunk can be disregarded, and finally : 



T = T! + T 2 + T 3 = 3-952 + 0-281 + 1-812 = 6-045 kgm. 

 on the average 6 kilogrammetres per step. 



It is obvious that the above numerical results are only true for 

 a particular subject walking in a particular manner. Never- 

 theless the results obtained by the above-mentioned scientists, 

 with subjects of the same weight and walking in the same way, 

 agree fairly well. 



For a pace of -778 metres in length the muscular work per kilo- 

 metre covered will be 



(\ v 1 000 



- = 7,712 kilogrammetres. 

 77o 



This result gives an idea of the amount of muscular work done in 

 walking. At the same time the vertical oscillation of the body, 

 which is a preponderating element in the expenditure of muscular 

 energy, is modified by the nature of the ground and the degree 

 of flexion of the legs. Regnault noted that in walking with bent 

 knees the pressure of the feet on the ground was more gentle than 

 in walking with the legs straight. 



Although the above computations are based on the results of 

 very careful experiments, they are not to be taken as rigidly 

 accurate. Furthermore, it must not be forgotten that the static 

 values of muscular contractions may be considerable. These 

 latter values cannot be registered by the above methods, and are 

 indeed only capable of any exact evaluation by measurements of 

 the consumption of oxygen. As walking is a function to which 

 man is specially adapted, it seems probable that the work done 

 at each step does not much exceed 4 kilogrammetres. 



273. The Rhythm of Walking. Marey made some experiments 

 on the effects of rhythm, the number of paces in unit time. The 

 apparatus, which he employed consisted of a horizontal track 

 500 metres in length, provided with electric contacts at intervals, 

 of 50 metres. 



He measured the variations in the length of the step as func- 

 tions of the rhythm or 

 cadence. Up to 150 

 paces per minute, the 

 length of the pace in- 

 creased, but above this 

 it diminished (vide fig. 

 256). In the case of a 

 walker 1 -67 metres high 

 (the same height as 

 Fischer's subject) the 

 maximum length of 

 the pace was found to' be 0-85 m. 



length ofltep___ 



80 SO /CO //0 /20 



fi$. 



/7O / 



Effects of the cadence. 



