Inversion and eversion are complex movements that involve the multiple plane joints among the tarsal bones of the posterior foot (intertarsal joints) and thus are not motions that take place at the ankle joint.
- Inversion is the turning of the foot to angle the bottom of the foot toward the midline.
- Eversion turns the bottom of the foot away from the midline.
The foot has a greater range of inversion than eversion motion. These are important motions that help to stabilize the foot when walking or running on an uneven surface and aid in the quick side-to-side changes in direction used during active sports such as basketball, or soccer (Picture 1 i).