For measuring hip internal/external rotation with a goniometer, which combination correctly describes the patient position, stabilization, and fulcrum placement?

• A. Position: Seated; Stabilize: Distal end femur to prevent abduction, adduction, or further hip flexion; Fulcrum: anterior aspect of patella; Stationary Arm: perpendicular to floor or parallel to supporting surface; Moving Arm: anterior midline of lower leg using the crest of tibia and point between malleoli for reference
• B. Position: Supine; Stabilize: Pelvis; Fulcrum: medial malleolus; Stationary Arm: along midline of tibia; Moving Arm: along midline of foot
• C. Position: Seated; Stabilize: Proximal thigh to prevent rotation; Fulcrum: posterior aspect of patella; Stationary Arm: along the longitudinal axis of the femur; Moving Arm: along the anterior midline of the lower leg
• D. Position: Standing; Stabilize: Pelvis; Fulcrum: anterior superior iliac spine; Stationary Arm: along the thigh; Moving Arm: along the leg

Answer: (A)

The key idea is to isolate hip rotation when measuring with a goniometer by using a position and setup that minimize compensations from other joints. In seated hip rotation, you stabilize the thigh so the distal femur cannot move in abduction, adduction, or further hip flexion, which keeps the motion coming from the hip joint itself. Placing the goniometer’s axis at the anterior aspect of the patella lines up with the hip’s rotation axis, ensuring the measurement reflects turning of the thigh around the hip. The stationary arm is kept perpendicular to the floor to provide a stable reference, while the moving arm follows the anterior midline of the lower leg along the tibial crest toward a reference between the malleoli, so the arc of rotation is tracked along the leg as it turns.

This combination is preferred because it uses a reliable, consistent axis (patellar anterior point) and a stable framework (distal thigh stabilization and a vertical stationary arm) to measure pure hip rotation. Other setups place the fulcrum in less appropriate locations or allow additional movements (like pelvis or knee motion) that can contaminate the reading, or use a stance (standing) that makes isolation of hip rotation more difficult.