20 PERSONAL APPEARANCES IN HEALTH AND DISEASE. 



longer move in concert, and lose their parallel action. 

 Change of form is also obvious enough from wasting of 

 particular groups of muscles. We may only instance the 

 flattening of the back of the forearm in lead-palsy, where 

 the muscles which bend the hand backwards are especially 

 attacked, so that the hand falls and cannot be raised 

 the condition known as " wrist-drop." 



Then again, weakening of the muscles of the back (as 

 produced by enforced sitting on benches without support 

 to the back) is one cause of what is called lateral cur- 

 vature of the spine, where the curve to one side which 

 the spine has in the loins is greatly increased, so much 

 so, that the shoulder on the side to which the curve is 

 directed is lower than its fellow; and a curve in the 

 opposite direction, causing projection of the blade-bone, 

 forms in the dorsal region. 



Club-foot is in a large majority of cases due to mus- 

 cular defect a defect which may be present to a' certain 

 degree at birth, or which may arise from an unnoticed 

 paralysis in early childhood. The most common form of 

 this is, that where the heel is raised, and the subject walks 

 not on the sole but on the toes, or more frequently on the 

 side of the foot. The strong tendon which passes from 

 the calf muscle to the heel is in such cases contracted, the 

 muscles themselves being wasted from their long enforced 

 inactivity, so that the leg appears small and shrivelled. 



