LOCOMOTION 



361 



Fischer found, as the result of careful experiments with 103 

 soldiers, that every person's walk has its own individual char- 

 acter. Although his subjects were all very much alike, yet their 

 steps were dissimilar both in length and duration. He came to 

 the conclusion that there is no universal type of walking. 



Demeny f 1 ) found that the period of double support is percep- 

 tible up to 200 paces per minute, and that the duration of this 

 period decreased rapidly above 80 paces per minute, being 175 

 thousandths of a second at this speed, and only 50 thousandths 

 at 200 paces per minute. 



The lateral oscillations of the trunk decrease with rapid 

 cadences, because the feet tend to come nearer to the line of 

 progression. It must also be pointed out that by reducing the 

 period of movement of the legs, the synchronous oscillation of 

 the bust, which has a relatively long period, is impeded. In 

 the same way the arms bend and reduce their amplitude of oscil- 

 lation. 



It would therefore seem that, as far as the above conditions are 



concerned, a given distance can 

 be covered more economically 

 by fast walking than by walking 

 slowly. On the other hand, the 

 expenditure of muscular energy 

 increases generally with increase 

 in the number of steps per 

 minute. 



Fig. 257 shows the variation 

 of the muscular work with the 

 number of paces per minute. It 

 is based on Marey's results, who 

 found that the work increased 

 up to 110 paces per minute, that 



from 110 to 130 paces it was practically constant (this is, therefore 

 the best pace), while at over 140 paces the work rises rapidly, as 

 the curve shows. We see, therefore, that beyond a certain point, 

 walking becomes so tiring that it is preferable to run. 



274. Conclusion. From the curve in fig. 257 we can calculate 

 the work expended per metre-kilogramme ( 232). An adult, 

 weighing 65 kg., expends 7,712 kilogrammetres in covering 

 1 km. at a speed of 5,450 metres per hour. The expenditure is, 

 therefore : 



7712 

 65 X 1000 = kgm. per metre-kilogramme. 



80 



100 120 140 160 180 pas 

 F.o. 237. 



( x ) Demeny (Comptes Rendus Sciences, 25th June, 1885). 



