THE PRINCIPLES OF MYODYNAMICS. l6l 



was one inch and a half, while the depth of the 

 external condyle was one inch : This permitted 

 pressure to be made only on the internal con- 

 dyle. When the pressure was some 600 pounds 

 the internal condyle gave way and settled to a 

 level with the external condyle : And the two 

 condyles then sustained a pressure of over 

 2,200 pounds. As the cut surface was not quite 

 transverse antero-posteriorly, the condyles split 

 nearly in two from side to side. It would 

 appear, therefore, in this case, that one condyle 

 would be inadequate to sustain the pressure of 

 the quadriceps extensor, as obtained above, by 

 theoretical considerations — namely, over 1,000 

 pounds — and that both condyles of the femur 

 would be adequate to do the work required by 

 the myodynamic relations. 



143. The practical conclusions are : (i.) That, 

 under ordinary conditions, the cancellous tissue 

 of bone-ends can sustain the pressure applied to 

 it by the daily use of the muscles. (2.) That 

 the structural conditions of the bone-ends may 

 so change, on account of disease or injury that 

 the action of the muscles may cause absorp- 



