Ankle & Foot Structural & Biomechanical Evidence: suggestive

Jack Test Special Test

Orthopedic Physical Examination & Clinical Assessment Guide

Jack Test Orthopedic Special Test

What is it used for?

  • Assessing hindfoot and subtalar flexibility in cases of flexible flatfoot.
  • Evaluating the mechanical action of the plantar fascia (windlass mechanism).

How to Perform

  • Position: Have the patient stand or sit with weight on the foot.
  • Action: Manually dorsiflex the big toe.
  • Observation: Watch for the formation of a medial arch. Dorsiflexing the toe should pull the plantar fascia, shorten the foot, and elevate the arch (windlass effect).

Interpretation of Results

  • Positive Result (Normal/Flexible): The medial arch appears or increases when the toe is dorsiflexed.
  • Negative Result (Rigid): The arch does not change, suggesting a rigid flatfoot.

References