338 THE HUMAN MOTOR 



in the sagittal than in the transverse 

 direction . In this position the inher- 

 ent stability of the body is relatively 

 small, t 1 ) Hence neither of the 

 symmetrical attitudes are really 

 economical. 



It is otherwise in regard to the 

 asymmetrical pose (fig. 235). Here 

 the base of support is materially 

 increased by the separation of the 

 feet, and the weight of the body is 

 supported on one leg. This is the 



m real natural attitude of man and causes 



very slight oscillations. The centre of gravity of the body lies 

 almost exactly above the supporting leg, and in the direction of 

 the joint of the foot. Hence the muscles of the calf have but 

 little work to do. The difference of economy between the^ per- 

 pendicular attitude of the soldier standing at "attention" and 

 the natural attitude of true repose is as much as 22% as measured 

 by the consumption of oxygen. This subject has therefore 

 practical applications of great importance. ( 2 ) 



In the sitting position the base of support is much larger and 

 the stability of the body is therefore considerably increased. 

 Furthermore the muscles have but little to do. If we measure 

 the relative consumption of oxygen by an adult, first standing in 

 the easy attitude or Bequeme-Haltung (fig. 234), and next sitting 

 on a chair, leaning back with all the muscles of the legs relaxed, 

 we shall find that the average economy of the consumption of 

 oxygen is about 6% in favour of the sitting position. ( 3 ) The 

 relative expenditure of energy for the positions already considered 

 may be tabulated as follows : 



Sitting position ... ... ... ... ... ... 100 



Standing position, " haunched " pose ( 4 ) (fig. 235) ... 103 

 "easy "pose (fig. 234) ... ... 106 



" upright " pose (fig. 233) ... 125 



We see then that the sitting position is that which, under 



ordinary conditions, is the most rest.ful. 



Obviously, however, a recumbent attitude provides a far greater 

 base of support for the body when lying on a bed. In this attitude 

 the muscles are fully relaxed, and we find that the expenditure 

 of energy is some 7% or 8% less than in the sitting position. ( 6 ) 



(*) Leiterstofer, Das Militarische Training Usw., Stuttgart (1897). 



( a ) Zuntz and Katzenstein (Pfliiger's Arch., Vol. xlix, p. 361, (1891). 



() Jules Amar (Journ. de Physiol., March, 1911, p. 212). 



(*| A mean of values lying between 100 and 106. 



(*) Emmes and Riche (Amer. Journ. Physiol., vol. xxvii., p. 406, 1911). 



