AT THE TIME OF THE INCIDENT, EE WAS CLIMBING DOWN THE LADDER OF A CAT 793 OFF HIGHWAY TRUCK. PART WAY DOWN HIS FOOT SLIPPED OFF A LADDER RUNG AND HE BEGAN TO FALL BACKWARDS. WHEN HE GRABBED TH E LADDER WITH HIS LEFT HAND TO ARREST HIS FALL HE FELT A PAIN AND HEARD A POPPING SOUND IN HIS SLEFT SHOULDER.