Devices manipulate a hand of a user to provide pronation or supination assistance. Embodiments include an anchor; a hand engagement member operatively attached to the anchor and configured to receive and engage the hand of the user; a force applicator having a member portion and an anchor portion opposite the member portion, the force applicator attached to the hand engagement member proximate its member portion and attached to the anchor proximate its anchor portion; and a force application mechanism attached to the anchor and configured to cause a force to be applied to the force applicator causing the hand engagement member to manipulate the hand of the user to provide pronation or supination assistance. In some embodiments, the force application mechanism includes a non-incremental rotary mechanism. In some embodiments, a flexible tethering member attaches the anchor to the hand engagement member.