EMPLOYEE WAS PULLING ON HYDRAULIC HOSES, TO CLEAR THEM OUT OF THE WAY JUST OUTBY A RECENT ROOF FALL AREA IN PREPARATION OF RECOVERING THE FALL & EQUIPMENT INVOLVED. THE EMPLOYEE TRIPPED BACKWA RDS & TWISTED HIS LEG UNDER HIM & STRUCK SHOULDER ON A PULLER CHAIN. RESULTED IN FRACTURED LOWER LEG & SHOULDER DISLOCATION.