THE SKELETON 



37 



been weakened by the use of alcohol. Many surgeons dislike to operate 

 on an old drunkard. 



Posterior Curvature of the Spine. - -The spine (see Figs. 28, 31) has 

 two backward curves (opposite chest and hips) and two forward curves 

 (at loins and neck). The deformity called posterior curvature is chiefly 

 an exaggeration of the upper posterior curve. Round shoulders is the 

 slightest, and hunchback the most marked, degree of this 

 deformity. Causes : i, bending over the work while either 

 standing or sitting ; 2. slipping down in the seat, as in Fig- 

 ure 51 ; 3, working habitually with the work low in front, 

 as reading and writing at too low a desk (Fig. 49), or bend- 

 ing over while hoeing, sitting on the floor (Japanese and 

 Chinese) ; 4, weak muscles in the back ; 5, wearing shoes 

 with high heels; 6, binding the ribs down with tigJit cloth- 

 ing; 7, walking with the head drooped forward or the 

 chest flat ; 8, wearing suspenders without a pulley, or lever, 

 at the back ; 9, carrying the hands in the pockets. (Swing 

 the arms to keep the hands out of the pockets and break 

 the habit) : 10, wearing a coat or vest that is tight at 

 the back of the neck. This deformity is brought about by 

 stretching t /i e ligaments at the back side of the spine, and 

 by compressing the cartilages until tJiey become wedge- 

 shaped, with the thin part of the wedge in front. The 

 flexibility of the spine is a great advantage, but it in- 

 creases the risk of deformity. One of the most serious 

 evils of posterior curvature is a flat chest and restricted 

 breathing. 



Lateral Curvature of the Spine. -- A perfect spine curves 

 to neither side (Fig. 47), but is perfectly erect. The least 

 habitual lateral curvature is deformity. Causes: i, writing 

 at a desk that is too JiigJi ; 2, habitually carrying a book, 

 satchel, or other weight in the same hand ; 3. carrying the 

 head on one side (Fig. 46) ; 4, habitually standing with the 

 weight on the same foot ; 5, a certain defect of vision 

 (astigmatism. Chap. IX). 



To overcome Spinal Deformities.- -The work, or the 

 manner of doing the work, should be so changed as to give 

 extra labor to the neglected muscles. Avoid the habits 

 mentioned above as causing deformity. Sit and stand in 

 the manner described in the next paragraph. Sleeping on 

 the back upon a hard mattress without a pillow tends to ^ ut stra ined 

 cure posterior curvature and flat chest. and stiff. 



FIG. 37. - 

 INCORRECT 

 POSTURE. 



' 

 CORRECT 



