The subtalar joint axis is oriented at approximately how many degrees in the transverse plane?

The subtalar joint axis is oriented at approximately how many degrees in the transverse plane?

• A. 42 degrees in the transverse plane.
• B. 30 degrees in the transverse plane.
• C. 60 degrees in the transverse plane.
• D. 18 degrees in the transverse plane.

Answer: (A)

The subtalar joint rotates about an oblique axis, not aligned with a single plane. When you look at the projection of that axis in the transverse plane, it forms about 42 degrees. This orientation means that subtalar motion isn’t pure inversion/eversion; it couples with forefoot adduction/abduction because rotation around this oblique axis produces combination movements. That 42-degree transverse-plane angle is the standard figure used in practice to describe the subtalar axis, with some sources noting a small range around 40–45 degrees.

The subtalar joint rotates about an oblique axis, not aligned with a single plane. When you look at the projection of that axis in the transverse plane, it forms about 42 degrees. This orientation means that subtalar motion isn’t pure inversion/eversion; it couples with forefoot adduction/abduction because rotation around this oblique axis produces combination movements. That 42-degree transverse-plane angle is the standard figure used in practice to describe the subtalar axis, with some sources noting a small range around 40–45 degrees.