496 



APPLIED ANATOMY. 



DISTORTIONS ACCOMPANYING AFFECTIONS OF THE LOWER 



EXTREMITIES; 



The hip-joint is capable of flexion, extension, adduction, abduction, and rota- 

 tion. From the hip to the foot is a straight line; it can be shortened by disease 

 or injury of the bones of the thigh or leg, and in rare cases it can be lengthened by 

 disease at the epiphyses producing a more rapid growth than normal. It is almost 

 unknown for hyperextension of the hip to exist, because if the femur is intact the ilio- 

 femoral ligament prevents it. If the head is gone then the upper end of the femur 

 luxates upward and backward. Rotation likewise produces little effect on the posi- 

 tion of the greater trochanter. Deformities due to flexion, abduction, adduction, and 

 shortening are common. 



Increased Flexion. Fig. 497, A shows the normal position ; Fig. 497, B shows 

 hyperflexion at the hip. The increased forward bend of the pelvis necessitates an 

 increase in the lumbar curve in order to maintain the anteroposterior equilibrium. 



B. 



D. 



FIG. 497. Distortions accompanying affections of the lower extremity. 



Fig. A. Normal erect position, showing the normal inclination of the pelvis and normal relation of the 

 hack and buttocks. 



Fig. B. The pelvis has been tilted forward and downward, being flexed on the thighs; this results in an 

 increased hollowing of the back and an increased protrusion of the buttocks. 



Fig. C. The left thigh is adducted and the right abducted. If the left hip is ankylpsed in a position of ad- 

 duction, as shown, then the pelvis is tilted down on the right, inclining the spine immediately above in the same 

 direction. This moves the centre of gravity to the right, but is compensated by a shifting of the pelvis to the 

 left, thus bringing the vertical through the centre of gravity within the base of support. If the right hip is anky- 

 losed in abduction, the same condition results. In order to compensate for the uneven lengths of the limbs pro- 

 duced by tilting the pelvis, the knee of the apparently lengthened limb is bent. 



Fig. D. The solid outline shows the position assumed when the right leg is shorter than the left. By placing 

 a block under the short right leg the pelvis is raised to a horizontal line and the curves of the spine are straight- 

 ened, as shown by the dotted outline. 



Thus lordosis is produced with the accompanying hollowing of the back and projec- 

 tion of the buttock. This is common in coxalgia and congenital luxations of the hip. 

 Hyperadduction and Hyperabduction. If there is hyperadduction, as 

 when one hip is ankylosed in a position of adduction, as shown in the left limb (Fig. 

 497, C), the pelvis is carried up toward the left; to restore the balance the spine is 

 inclined to the right. If, however, the right limb is hyperabducted or fixed in a 

 position of abduction, then in assuming the upright posture the right hip descends 

 and the spine is inclined toward the side of the affected limb, as seen in the right hip 

 of Fig. 497, C. In treating these conditions the spine can be brought straight by 



