MOVEMENTS OF HIP-JOTXT. 173 



FI' : .'->'i ami extension. In the swinging movement flexion is freer Swinging 

 than extension, the thigh being capable of such elevation as to touch m 

 the belly. 



While swinging, the head of the femur revolves in the bottom motion of 

 of the acetalmlum, rotating around a horizontal axis ; and the foj^[ 

 rapidity and extent of the movements do not endanger the security 

 of the joint, the head of the bone not having any tendency to 

 escape. 



In extension the strong ilio-femoral ligament (the inner band checks to 

 .......... , , ., - ^ movement. 



especially) is tightened, and stops the movement. Flexion is not 



FlG. 65. HlP- JOINT OPENED. 



a. Part of the capsule. pubic, and d, its ischial attach- 



6. Jnterarticular ligament : c, its ment. 



naturally arrested by the ligaments of the joint, but by the meeting 

 of the soft parts of the thigh and abdomen. 



In abduction and adduction the femur is removed from, or brought Lateral 

 towards, the middle line of the body, and, of the two, abduction is movement 

 the more extensive. 



In both states the head moves in the opposite direction to the motion of 

 shaft. Thus, as the femur is abducted, the head descends, and a thehead J 

 great part of the articular surface projects below the acetabulum ; 

 and when the limb is raised to its utmost, the upper edge of the 

 neck meets the edge of the socket, so as to prevent further motion. 

 As the limb descends and approaches the other, the head rises in 



