Elevation of the arm in the scapular plane with the arm internally rotated and the thumb down. Elevation of the arm in the sagittal plane. Horizontal adduction from the prone position with arm externally rotated. In a seated position, the hands are placed upon the seat, and the body is lifted from the chair by extending the upper extremities. A rehabilitation program often succeeds in patients with atraumatic instability.
Traumatic dislocations appear to respond less favorably.