Abstract: Apparatus for positioning a human arm for shoulder surgery which includes a clamp for attaching the apparatus to a support, a bracket movably mounted in the clamp, and a forearm pad movably mounted on the bracket and adapted to support the forearm portion of the human arm. A pulley support arm is movably mounted on the bracket and a pulley is mounted on the pulley arm. An upper arm cuff is provided for attachment to the upper arm portion of the human arm. A flexible strand is connected at an upper end to the cuff, extends along the pulley and, at a lower end thereof, receives a selected weight. The weight, in response to gravity, puts tension on the strand which in turn pulls the cuff, and thereby the human upper arm, outwardly from the body to which the arm is appended.