A modular sling and pillow system for setting an appropriate abduction angle and external rotation angle in a shoulder joint. The patient's forearm is secured in a sling. An abduction pillow is fastened to the patient's side, just above the waist and facing the elbow contained within the sling. An appropriate external rotation wedge is then attached to the abduction pillow. The external rotation wedge is preferably fastened to the abduction pillow using VELCRO fasteners so that it can be easily removed and replaced. The abduction pillow pivots the upper arm outward. The external rotation wedge rotates the upper arm by moving the wrist out away from the body. The sling is attached to the external rotation wedge so that an integral brace comprising the sling, the external rotation wedge, and the abduction pillow is created.