An ankle brace for restricting dorsiflexion and promoting plantarflexion of the foot relative to the leg. The ankle brace includes a lower leg assembly worn on the wearer lower leg, a foot assembly worn on the wearer's foot; and one or more hinge assemblies rotatably connecting the lower leg assembly to the foot assembly. The hinge assembly provides a positive or resistive force on the top foot assembly to prevent dorsiflexion and/or to promote plantarflexion to reduce knee injuries.