APPENDIX. 



CONTAINING A DESCRIPTION OF THE ATTITUDES OF STAND- 

 ING, WALKING, SITTING, AND LEANING; TOGETHER WITH 



REMARKS AND OBSERVATIONS ON SPINAL DISTORTIONS, 

 AND THE USE OF STAYS. 



911. THE attitudes which the human frame is capable of 

 assuming, are exceedingly various, but physiologists have 

 reduced them to two kinds, or classes ; the active, and 

 the passive. The former includes all such as require the 

 action of the muscles, as standing or walking ; the lat- 

 ter, such as require no muscular exertion, as when the 

 body lies prostrate. 



STANDING. 



912. When we stand on both feet, considerable mus- 

 cular effort is required to preserve the upright position ; 

 and still more when we stand on only one foot. In either 

 case, the centre of gravity, which is between the hips, 

 must be kept over the base. 



913. In the first attitude, the base of support is the 

 space between the feet, including the breadth of the feet 

 themselves in one direction, and their length in the other ; 

 and hence when the toes are turned outward, in standing 

 or walking, the base is enlarged. In the last, the base 

 is the single foot only. During this position of the body, 

 nearly all the muscles of the lower extremities, as well 

 as those of the back, are in a state of continual action ; 

 and this is the reason why we become sooner fatigued 

 \vhen standing still, than when walking, in which the 

 muscles are alternately contracted and relaxed. 



914. When we stand erect, the vertebral column trans- 

 mits the weight of the head, as well as of all the other 



