Sit , arm medially rotated and forward flexed to 90°+ axially loads the humerusin aproximal direction + moves the arm horizontally (crossflexion/ horizontal adduction)across the body• (+) : recurrent posterior instability is he production of a sudden jerk or clunk as thehumeral head slides off (subluxes) the back of the glenoid• When the arm is returned to the original 90° abduction position, a second jerk maybe felt as the head reduces.• Posteroinferior labral tea