234 



MOTION AND COORDINATION 



FIG. 104. A tendency 



toward spinal curvature (after 

 Mosher). 



of nerves pass between the ver- 

 tebrae to connect the spinal cord 

 with different parts of the body, 

 and two important arteries (the 

 vertebral) pass through a series 

 of small openings in the bones 

 of the neck to reach the brain. 

 Unnatural curves of the spine 

 throw different parts of the body 

 out of their natural positions, 

 diminish the thoracic and abdom- 

 inal cavities, and, according to 

 the belief of certain physicians, 



compress the nerves that pass from the cord to other parts 



of the body. Slightly misplaced vertebrae in the neck, by 



compressing the vertebral 



arteries, may also interfere 



with the supply of blood 



to the brain. 



How the Skeleton becomes 



Deformed. We are accus- 

 tomed to look upon the 



skeleton as a rigid frame- 

 work which can get out 



of its natural form only 



through severe strain or by 



violence. This view is far 



from being correct. On 



account of their necessary 



freedom of motion, the 



bones, especially those of 



FIG. 105. Effect on spinal column 



of improper position in writing. ( From 

 Pyle's Personal Hygiene,") 



the spinal column, are easily slipped from their normal 

 positions; and where improper attitudes are frequently 



