174 



DISSECTION OF THE LEG. 



state of the 

 ligaments. 



Dislocation 

 in lateral 

 movements. 



Circum- 

 duction. 



Rotation 



inwards, 



and 

 outwards. 



Examine 

 attachment 

 of muscles. 



the socket of the joint, and is securely lodged, finally, in the deepest 

 part of the cavity. 



In abduction, the pubo-femoral ligament and lower part of the 

 capsule are tightened over the projecting head of the femur, the 

 upper part being relaxed. And in adduction, the outer band of 

 the ilio-femoral ligament is rendered tense and arrests the movement. 



Dislocation may take place in both these lateral movements, the 

 edge of the cotyloid cavity serving as the fulcrum, 011 which the 

 femur can be lifted out of the hollow, and particularly in abduc- 

 tion with some flexion, for there the head of the femur is against 

 the thin under-part of the capsule. 



In circumduction, the four kinds of angular motion above noticed 

 take place in succession, viz., flexion, abduction, extension, and 

 adduction ; and the limb describes a cone, the base of which is at 

 the foot, and the apex at the centre of the head of the femur. 

 This movement is less free than in the shoulder-joint. 



There are two kinds of rotation, internal and external ; in the 

 former, the great toe is turned in ; and in the latter it is moved 

 outwards. 



In rotation inwards, the head of the femur glides backwards 

 horizontally across the acetabulum, the great trochanter coming 

 forwards ; and the shaft of the bone revolves around a line internal 

 to it, which passes from the centre of the head to the inner condyle. 

 During this movement the posterior half of the capsule is put on 

 the stretch, and the anterior is relaxed. 



In rotation outwards, the head of the bone turns forwards in the 

 cotyloid cavity, and the great trochanter is brought backwards. 

 The outer band of the ilio-femoral ligament is tightened and checks 

 the movement. 



Dissection. After the limb is removed, the attachments of all 

 the muscles in the thigh are again to be examined carefully before 

 the dissection of the leg is undertaken. The muscles should not be 

 removed from the femur, but about two inches of each left attached 

 to the bone. 



SECTION IV. 



THE FRONT OF THE LEG. 



Surface 

 marking. 



In the leg 

 the tibia is 

 superficial, 



Directions. Before the dissection of the leg is begun, the student 

 should make himself acquainted, as in the thigh, with the promi- 

 nences of bone and muscle on the surface, and with the markings 

 which indicate the position of the larger vessels. 



Prominences of bone. The bones of the leg can be traced beneath 

 the skin from the knee to the ankle-joint. At the inner and fore 

 part is the tibia, which is subcutaneous in all its extent, and is 

 limited in front and behind by a sharp edge. Above, it presents 

 in front a prominent tubercle into which the ligament of the 



