Abstract: A first rigid elongated plate has first and second ends, a first end being hingedly attached to a first end of a rigid link to swing freely towards and away from one side of the link within a predetermined included first arc. A second rigid elongated plate, having first and second ends, is hingedly attached to the other end of the link to swing freely towards and away from the one link side within a predetermined included second arc. A flexible envelope encloses the first and second plates and the link to retain the plates and link in end to end hinged relation. Strap members transversely extend from the envelope and are wrappable around the user's hand, wrist, and forearm to hold the envelope, plates, and link in supporting relation thereto.