Thick shells and medially wedged posts increase foot orthoses medial longitudinal arch stiffness: an experimental study.

Background: Foot orthoses (FOs) are commonly prescribed devices to attenuate biomechanical deficits and improve physical function in patients with musculoskeletal disorders. It is postulated that FOs provide their effects through the production of reaction forces at the foot-FOs interface. An important parameter to provide these reaction forces is their medial arch stiffness.