The usual term for the increase in such an angle would be extension, but in order to emphasize the relation between foot and hand, this action is instead termed plantar flexion . However, this would decrease the angle between the body segments, and action usually termed flexion. Since the term, plantar flexion, has been used for the opposite action, this is now referred to as dorsiflexion . The resulting angle of rotation is oblique, from the medial side of the heel to the lateral side of the mid-foot. Inversion is the action of turning the sole of the foot inward, towards the opposite foot.
Eversion is the movement of turning the sole of the foot outward, away from the midline.
In the hand and foot, a specific application is utilized for the general terms abduction and adduction . This action is termed opposition . The actions of abduction and adduction were previously described with regard to movements relating to the body as a whole. Opposition Opposition is a special action of the hand, whereby the thumb and little finger are brought around to touch the fingertips. This action occurs at the joints between the carpal bones and the metacarpals of the thumb and little finger.