Which axis represents the medial-lateral GRF component?

Which axis represents the medial-lateral GRF component?

• A. X-axis
• B. Y-axis
• C. Z-axis
• D. Horizontal-axis

Answer: (A)

Medial-lateral refers to the side-to-side direction in the horizontal plane, so the force component in that direction is captured along the X-axis. In the standard biomechanics coordinate system used for gait and ground reaction forces, the X-axis runs left–right, the Y-axis runs front–back (anterior-posterior), and the Z-axis runs vertical (up–down). Therefore, the medial-lateral GRF component corresponds to the X-axis, while the vertical component is along Z and the anterior-posterior component along Y. Horizontal-axis is too vague to specify the exact left-right direction here.

Medial-lateral refers to the side-to-side direction in the horizontal plane, so the force component in that direction is captured along the X-axis. In the standard biomechanics coordinate system used for gait and ground reaction forces, the X-axis runs left–right, the Y-axis runs front–back (anterior-posterior), and the Z-axis runs vertical (up–down). Therefore, the medial-lateral GRF component corresponds to the X-axis, while the vertical component is along Z and the anterior-posterior component along Y. Horizontal-axis is too vague to specify the exact left-right direction here.