THE PRINCIPLES OF MYODYNAMICS. 1 29 



axis. The head and neck of the femur may be 

 looked upon as a lever. The entire femur is a 

 bent lever. The acetabuhim is the fulcrum. When 

 the femur is the movable bone, the components 

 of the muscles that span the hip-joint may be 

 determined on the principle of a lever of the 

 third order. When the body rests on the head 

 of the femur, and is moved by the muscles that 

 span the hip-joint, these muscles act on the 

 pelvis as the power of a lever of the first order. 

 The femur may be rotated about forty-five 

 degrees. The femur may be adducted from a 

 line parallel with the long axis of the body 

 about thirty degrees. The femur may be ab- 

 ducted from a line parallel with the long axis of 

 the body about thirty degrees. The lateral 

 motion of the lower limb will therefore be not 

 far from sixty degrees. The femur may be 

 flexed till the thigh comes in contact with the 

 surface of the abdomen. The femur can be 

 extended so that the condyles will be somewhat 

 back of the long axis of the body prolonged. 

 124. It requires a few words in regard to the 



