Last reviewed 01/2018

Flexion is the verb meaning to bend the body or part of a body in an anterior direction. For example, bending forward to touch the toes involves flexion of the trunk. However, there are exceptions:

  • knee flexion is bending of the joint in a posterior direction
  • thumb flexion is movement of the digit across the plane of the hand
  • flexion of the foot is described in terms of flexion of the dorsal surface - dorsiflexion

Alternatively, it indicates the movement to make a reduced angle between two bones or body regions.

Flexion is the opposite of extension.