An arm support and positioning assembly is provided that includes a vertical member, an engagement member and a horizontal member having one end engaged with the vertical member through a ball joint assembly and the other end affixed with the engagement member through a wedge lock. The engagement member receives and retains a patient's arm support during the surgical or medical procedures. The vertical member is attached to the clamp support assembly affixed with the operating table. The ball joint assembly includes a first hinge plate, a second hinge plate, and a ball joint having an elongated ball neck on one end and a spherical ball on other end. The ball shape end allows the horizontal member to rotate at a varied angular position with respect to the vertical member thereby providing a greater degree of adjustability to the surgeon.