THE PRINCIPLES (3F MYODYNAMICS. IIJ 



and is resisted by the anterior crucial ligament, 

 and thus has its force brought on the joint- 

 surfaces, so that the two rectangular components 

 hold the fixed and movable bones together with 

 a force equal 391 pounds. — Add to this the 

 weight of 5o pounds, and the mutual pressure 

 of the joint-surfaces of the tibia and femur 

 equals 441 pounds. 



109. See Fig. 26 : The description is the 

 same as in the first instance — except that the 

 femur and the tibia meet at an acute angle. 

 The bent lever is P d W, having a fulcrum F d. 

 The myodynamic angle is C P D — the conjugate 

 axis of the base of the tibia prolonged being one 

 side of the component triangle. In this case the 

 rectangular components are equal. The moving 

 component DC equals 35o pounds as before, 

 when the weight equals 5o pounds, and the dis- 

 placing component P D equals 35o pounds. 

 The force of the quadriceps, from which the two 

 equal rectangular components are resolved, is 

 therefore equal 494 pounds — and the pressure 

 of the condyles of the femur on the base of the 

 tibia would be 644 pounds. 



