THE PRINCIPLES OF MYODYNAMICS. 37 



twice as great as the myodynamic triangle : — 

 Then the same conclusions may be drawn as in 



(.,) (2), (3), 22 B. 



25. In a bony lever of the third order, let a c 

 i, be a movable bone, o c, a fixed bone, c, their 

 joint, m, the contracting muscle, whose origin 

 and insertion are at o and i : See Figs. 1 1, 12, 

 1 3. The power is at i, the weight at a, and the 

 fulcrum at c. The myodynamic triangle is o i c. 

 And the myodynamic angle is o i c. 



(a) The myodynamic angle is acute in Fig. 1 1 , 

 right in Fig. 12, and obtuse in Fig. 14. 



(b) From the origin of the contracting muscle 

 draw a perpendicular to the long axis of the 

 movable bone — prolonged if necessary. Com- 

 plete the rectangle o b i d, whose diagonal is 

 the long axis of the contracting muscle. 



(c) Again as before, when the myodynamic 

 angle is right, there will be one rectangular com- 

 ponent. 



(d) Also as before, when the myodynamic 

 angle is acute or obtuse, there will be two rect- 

 angular components. 



26 A. In this case also, when the myodynamic 



