In the ankle joint, what is the approximate axis orientation in the transverse plane?

In the ankle joint, what is the approximate axis orientation in the transverse plane?

• A. 8 degrees in transverse plane
• B. 0 degrees
• C. 5 degrees
• D. 10 degrees

Answer: (A)

The ankle’s axis of rotation is not aligned with a single anatomical plane; it sits obliquely in three dimensions. In the transverse (horizontal) plane, the axis is rotated by about 8 degrees from a pure sagittal alignment. This small tilt means that when the ankle moves through dorsiflexion and plantarflexion, there’s a subtle amount of rotation in the transverse plane as well, so motion is not purely in one plane. Eight degrees is the commonly cited approximation for how much the axis deviates in the transverse plane, making it the best choice among the options. A zero degree figure would ignore this natural obliquity, while 5 or 10 degrees are less representative of the typical orientation taught in mechanics of the ankle.

The ankle’s axis of rotation is not aligned with a single anatomical plane; it sits obliquely in three dimensions. In the transverse (horizontal) plane, the axis is rotated by about 8 degrees from a pure sagittal alignment. This small tilt means that when the ankle moves through dorsiflexion and plantarflexion, there’s a subtle amount of rotation in the transverse plane as well, so motion is not purely in one plane.

Eight degrees is the commonly cited approximation for how much the axis deviates in the transverse plane, making it the best choice among the options. A zero degree figure would ignore this natural obliquity, while 5 or 10 degrees are less representative of the typical orientation taught in mechanics of the ankle.