274 PHYSIOLOGY AND HEALTH. 



CHAPTER VII. 



Bones are Levers; Muscles are moving Powers. Muscles act at 

 Disadvantage. Power sacrificed to Convenience of Action. 

 Especially in the Fingers and Toes. Muscles cooperate to pro- 

 duce one Motion. Rapidity and Precision of Muscular Action. 

 Illustrated by Piano-Forte Player. Violinist. Writing. 

 Carpenter. 



631. THOSE muscles which are situated at a distance 

 from the object to be moved work at great disadvantage. 

 If that muscle which, bends the elbow were placed in the 

 bend of this joint, and its lower end attached to the lower 

 end of the fore-arm (Fig. LVI. b) instead of the natural posi- 

 tion at the elbow, it would act with more power than it now 



FIG. LVI. Upper Arm Biceps misplaced. 



a, b, Biceps attached to wrist. 



does. But muscles so situated would interfere very much 

 with the freedom of the movements, and with the application 

 of the limbs to a great variety of purposes, and be very 

 awkward. 



632. In motion, the bones_are levers, a'hd the muscles 

 are the moving powers. The bones of the fote-arm are 

 fixed very near its end, to the extremity of the bone of the 

 upper arm. The upper bone is the fulcrum or point of 

 support ; the muscles that move this lower arm are at 

 tached to it within less than half an inch of the fulcrum, 

 while thp whole bone or lever is ten to twelve inches in 



