THE PRINCIPLES OF MYODYNAMICS. 1 33 



minimus has a more advantageous position and 

 dynamic relation than the rotating component 

 of the triceps rotator. 



(2.) The rotating component of the triceps 

 rotator equals the rotating component of the 

 gluteus minimus plus the pressure on the fe- 

 moral head in the direction of the motion of the 

 rotating component of the triceps rotator. 



(3.) But when the articular ligaments and the 

 conformation of the joint cause the combination 

 of the muscular components under considera- 

 tion, the pressure on the head of the femur is 

 equal the sum of the contractile energy of the 

 two muscles. 



131. (a.) To a certain extent, a long femoral 

 neck has favorable dynamic relations : — 



( I .) This is true in regard to the lateral strain 

 caused by the moving components of the con- 

 tracting muscles. 



(2.) This is not true in regard to the pressure 

 caused by the entire force of the contracting 

 muscles. 



(b.) The weakest part of the femoral neck is 

 at its junction with the head : — 



