Which statement about the ankle joint axis orientation is true?

Which statement about the ankle joint axis orientation is true?

• A. It is approximately 0 degrees in the transverse plane.
• B. It is approximately 20-30 degrees in the frontal plane.
• C. It is approximately 8 degrees in the transverse plane.
• D. It is approximately 60 degrees.

Answer: (C)

The ankle joint axis is not aligned with a single cardinal plane; it runs obliquely through the joint, with a small tilt in the transverse (horizontal) direction. This means there is a slight deviation from the sagittal plane when you trace the axis, typically about 8 degrees. That modest transverse-plane tilt explains why ankle motion isn’t purely dorsiflexion-plantarflexion and why some rotation accompanies flexion and extension. So the statement about roughly 8 degrees of tilt in the transverse plane reflects this real, small obliquity of the axis. The other options describe implausible or larger-than-expected orientations (0 degrees in the transverse plane would imply no such tilt; 20–30 degrees in the frontal plane or 60 degrees are not consistent with the known axis orientation).

The ankle joint axis is not aligned with a single cardinal plane; it runs obliquely through the joint, with a small tilt in the transverse (horizontal) direction. This means there is a slight deviation from the sagittal plane when you trace the axis, typically about 8 degrees. That modest transverse-plane tilt explains why ankle motion isn’t purely dorsiflexion-plantarflexion and why some rotation accompanies flexion and extension.

So the statement about roughly 8 degrees of tilt in the transverse plane reflects this real, small obliquity of the axis. The other options describe implausible or larger-than-expected orientations (0 degrees in the transverse plane would imply no such tilt; 20–30 degrees in the frontal plane or 60 degrees are not consistent with the known axis orientation).