350 



THE HUMAN MOTOR 



The knowledge of the moments of inertia leads to that of the 

 work of the oscillation, the angular speed being <o, : 



T = lco 2 . 



In the above calculations it is assumed that no load is carried 

 by the man. If the various members carry any load, it is obvious 

 that the centres of gravity and the moments of inertia will have 

 different numerical values. The writer's object, in the above 

 calculations has been to show, quite simply, that it is possible to 

 determine the above values in any given case. Of this Braune 

 and Fischer have given ample proof, based both on experiment and 

 on fundamental theory. By chronophotography the magnitude 

 and velocity of movements in their various phases can be studied 

 with accuracy. The German scientists, above mentioned, em- 

 ployed Marey's system of geometrical chronophotography illum- 

 inating the points and lines to be photographed by means of 

 Geissler tubes.( l ) 



268. Human Locomotion. Locomotion which is the movement 

 of the human body as a whole may be divided into two depart- 

 ments, terrestial locomotion and aquatic locomotion. Both obey 

 the same laws of muscular action. 



The most familiar form of terrestial locomotion is Walking. 

 But we have also the motions of Crawling (in which the points of 

 contact of the body with the ground are increased) ; Running 

 and Jumping (in which the amount and duration of such contact 

 is reduced) and Climbing (in which the weight of the body is sup- 

 ported by the arms.) 



A B C 



FIG. 249. 

 Different phases of a simple step; the subject goes from A to C. 



(') Braune and Fischer, Der Gang des Menschen, Part I. (Abhand. d. Math. 

 vol. xxii., 1985). 



