Universal ankle-foot orthosis
AssigneeThe Regents of the University of Michigan
InventorsNikko Van Crey, Elliott J. Rouse
Life of this patent
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Abstract
An ankle-foot orthosis includes a leg portion and a foot portion. The foot portion is biased toward an equilibrium angle with respect to the leg portion, and the equilibrium angle is adjustable to accommodate different users'natural stance. An adjustable leg stay permits fitting the orthosis to multiple different users, and the orthosis can be fitted to either leg of a user with only a foot plate change. A variable stiffness spring and cam system modulate ankle joint stiffness according to a pre-defined cam profile. The contact point of the cam system is forward of the user's heel and thus closer to the ankle joint, enabling reduced-size components. Two rotational degrees of freedom are provided in plan-tarflexion/dorsiflexion and inversion/eversion.
Claims38
An ankle-foot orthosis comprising a leg portion and a foot portion biased toward an equilibrium angle with respect to the leg portion, wherein the equilibrium angle is adjustable.
An ankle-foot orthosis comprising a leg portion and a foot portion having an equilibrium angle with respect to the leg portion, wherein a biasing force is applied to the foot portion anterior to the heel of a person wearing the orthosis when the foot portion is away from the equilibrium angle.
An ankle-foot orthosis comprising a leg portion and a foot portion coupled at a pivot joint having two rotational degrees of freedom.
An ankle-foot orthosis configured for use on one of:
- a right leg or a left leg,
- wherein the orthosis is convertible for use on the other leg by replacing only a foot plate of the orthosis.
A method of fitting an ankle foot orthosis to a person, the method comprising the step of adjusting an equilibrium angle of the orthosis to match a stance angle of the person.
An ankle-foot orthosis comprising a leg portion and a foot portion biased toward an equilibrium angle about a pivot joint, wherein the pivot joint has a non-linear torque-angle function.
Dependencies are inferred from the claim text.