Orthosis with variable motion controls

Abstract

A releasable controlled-motion ankle-foot orthosis includes an elongated shell adapted for releasable attachment to the lower leg above the ankle joint, a foot support adapted for releasable attachment to the foot, and lateral and medial controlled-motion ankle joint assemblies attached to the shell and to the foot support in alignment with the axis of rotation through the ankle joint. Each ankle joint assembly includes a rigid support plate affixed at one end to the shell, extending across the ankle joint, and affixed at the other end to the foot support. Sets of cam members in matching pairs are used interchangeably for controlling range of motion in plantar flexion and dorsiflexion. Each individualy selectable cam member is rotatably mounted to the support plate for contact with a stop on the support plate to control angular motion. Each cam member has a unique combination of anterior and posterior cam surfaces that contact or rotate into contact with corresponding anterior and posterior portions of the stop to provide different selective angles of rotation in plantar flexion and dorsiflexion, including extended range of motion in plantar flexion and dorsiflexion, a stop in dorsiflexion combined with controlled angular motion in plantar flexion, and vice versa, no motion in either plantar flexion or dorsiflexion, and a (+) (-) cam to accommodate alterations to lessen angular motion control.