Question

3. IL31 The pictures below represent a person's right hip. Figures (a) and (b) represent a normal hip, figure (c) represents what is called coxa valga and figure (d) represents what is called coxa vara. In the normal case, the angle of inclination (between the axis of the shaft of the femur and the neck of the femur) is 1250. Coxa valga represents a larger than normal angle of inclination and coxa vara, a smaller than normal angle. The force Fi represents the amount of weight that is pushing vertically down on the femur-acetabulum joint. Assume that this force is 70 pounds and that the angle between the vertical and the shaft of the femur is 5°. Consider the normal case (fig. b) and answer the following. a. How much force is acting along the axis of the neck of the femur? NOTE: This force is compressing the joint. b. How much force is acting perpendicular to the axis of the neck of the femur? NOTE: This force is causing slippage at the joint. c. Which of the three case (figures (b), (c) or (d)) represents the most stable situation? 70 lb 70 lb 70 lb 5° 125° at the femur at the femur liofemoral ligament Greater trochanter Pubofemoral ligament angle of inclination

Answer 1

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