Ankle (plantar flexion and dorsi flexion).

The idea

The ankle is a hinge joint, so it allows movement in one plane: plantar flexion and dorsiflexion. Plantar flexion points the toes downwards and away from the shin, increasing the angle between the foot and the front of the lower leg; it occurs at take-off in a jump or when standing on tiptoe. Dorsiflexion pulls the toes upwards towards the shin, decreasing that angle; it occurs as the heel strikes the ground in walking or running and as the foot prepares to absorb landing forces. In multiple-choice questions you must decide which of the two movements is described by the position or phase of the foot in the stem, and you must not confuse ankle movements with knee or hip movements.

What earns the marks

• The ankle is a hinge joint that allows plantar flexion and dorsiflexion.
• Plantar flexion points the toes downwards and away from the shin.
• Dorsiflexion pulls the toes upwards towards the shin.
• Plantar flexion occurs at take-off in a jump or when rising onto the balls of the feet.
• Dorsiflexion occurs as the heel strikes the ground during walking or running.
• Dorsiflexion prepares the foot to absorb landing forces.
• The two movements are opposites and occur in the same plane at the ankle.

Common mistakes and how to put them right

• Reversing the two terms.

  Put it right: The misunderstanding is that plantar flexion lifts the toes towards the shin, but the correction is that plantar flexion points the toes downwards and dorsiflexion lifts them upwards.

• Treating the ankle as a ball-and-socket joint.

  Put it right: The misunderstanding is that the ankle allows sideways movement, but the correction is that it is a hinge joint allowing only plantar flexion and dorsiflexion.

• Confusing ankle movement with knee movement.

  Put it right: The misunderstanding is that bending the knee is dorsiflexion, but the correction is that dorsiflexion happens at the ankle when the toes move towards the shin.

• Ignoring the phase of the action.

  Put it right: The misunderstanding is that any foot movement in a jump is plantar flexion, but the correction is that the landing phase typically involves dorsiflexion as the foot prepares to absorb force.

Exam tips

• Picture the foot in the position described in the stem: toes down means plantar flexion, toes up means dorsiflexion.
• Eliminate options that name movements of the knee or hip, because the stem asks specifically about the ankle.
• Use a familiar action such as standing on tiptoe or a heel strike to check which movement the option describes.