Hip abduction/adduction ROM: which option correctly states the moving arm?

• A. Midline of tibia
• B. Midline of pelvis
• C. Midline of femur
• D. Dorsal midline of foot

Answer: (C)

For hip abduction and adduction, the moving arm should follow the moving segment, which is the thigh. Aligning the moving arm with the midline of the femur (from the greater trochanter toward the knee) makes the measured angle reflect how far the thigh moves away from or toward the midline of the body. Using the midline of the tibia would track the lower leg and knee, the midline of the pelvis would reflect trunk/pelvis movement, and the dorsal midline of the foot would measure ankle/foot position, not the hip ROM.