The invention relates to a method and apparatus for manipulating a shoulder joint, by independently manipulating the upper arm in two directions. One direction is “longitudinal”, wherein the upper arm moves substantially along its longitudinal axis. The second is “lateral”, in which the upper arm moves laterally from a first to a second position, with the second position being spaced apart from the first and such that the longitudinal axes of the upper arm in the two positions are substantially parallel. The apparatus is adjustable, but includes two parts stationary during use; an elongate yet platelike “upper arm supporting plate” configured to be situated under the upper arm of the patient (extending proximate the armpit and extending proximate the elbow) and an elongate “forearm member” configured to be positioned proximate the forearm of the user when the user's arm is in position bent approximately 90 degrees. Two other elements cause controlled movement of the arm relative to the structure so the surgeon may perform the desired procedure. These inflatable bladders may be selectively inflated or deflated to provide a desired effect. These can be referenced as an “upper arm bladder” and a “forearm bladder”, although they may be also referenced as first and second bladders, although not necessarily in that order. By inflating the upper arm bladder, the upper arm is moved away from the upper arm supporting plate, causing perpendicular (a.k.a., “lateral”) force to occur to elevate the humerus perpendicularly from the glenoid to allow good clean glenoid work.