ANIMAL LOCOMOTION. 97 



THE MOVEMENTS OF THE HUMAN SUBJECT. 



The motions of the hands and feet are easentially those of the 

 quadruped. In the series 258, the man rising from a recumbent 

 position on the ground first uses the left arm for support, subse- 

 quently transfers the weight to the right, and after gaining the up- 

 right position retains the hand last named as though it were in 

 the first stage of the recover, as seen in the foot of the quadruped. 

 The dictum made in connection with the flexor muscles aiding the 

 foot of the quadruped to maintain itself on the ground is here ex- 

 emplified (p. 42). It is interesting to note that the moment the 

 hand leaves the ground it becomes markedly flexed. 



Gait. 



In series 69 the position of the arms (being thrown back at the 

 time that the hind leg of the opposed side is also thrown back) 

 sustains the assertion that the motion of the limbs of man is heter- 

 ochiral. The chief distinction between the gait of man and that of 

 the quadruped is the degree of torsion of the vertebral column. 



For a good illustration of this torsion the figure of the boxer 

 (series 333) may be consulted. 



The Action of the Disengaged Limb. 



In series 811 and 312, while the right hand is engaged in 

 throwing a weight the left is in a state of great tension. The 

 limb is extended and the fingers are abducted. The fingers remain 

 extended save at the terminal phalanges, and show activity of the 

 interossei muscles. The position just named is suggestive and 

 presents a raison d'etre for the following reflections : 



First, that the unemployed arm is thrown into a state of ex- 

 citement because of the intentive strain on groups of muscles in 

 close co-ordination with them, — viz., the muscles of the limb of 

 the opposed side. The limb cannot repeat the exact attitude of the 

 one in use, and naturally tends to take on the form of the primal 

 limb. This form is that of a motion as though it were on the 

 ground and serving the purposes of progression. As is known 

 from the study of the quadruped, the limb after extension passes 

 gradually into flexion. It is evident that the interossei muscles 

 would not flex the terminal phalanges if the foot were on the 



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