Title: CMC I orthosis Abstract Orthosis for immobilizing a carpometacarpal joint of a thumb (CMC I) of a hand, comprising a joint supporting part (1) and a holding part (2), wherein the joint supporting part (1) comprises at least one anatomically shaped rigid ring-shaped element (3) configured to be slid onto the thumb to enclose part of a thenar eminence (T) of the thumb, wherein the holding part (2) comprises a rigid stabilizing part (4) that is fixed at a first position to the joint supporting part (1) and is configured to reach sideways along a first side of the hand to engage a pinky side of the hand, wherein the holding part (2) also comprises an adjustable stabilizing part (5) configured to reach along a second side of the hand to connect a second positon of the joint supporting part (1) to a distal end of the rigid stabilizing part (4).
