CLIMBING OFF A D11 BULLDOZER 222 ON THE LEFT SIDE TO CHECK THE LEVEL OF THE GROUND WHERE THE MINE ENGINEER HAD MARK, WHILE GETTING OFF HOLDING ON TO HAND RAILS, STUMBLE ON THE TRACK, LOST CONT ROL AND FELL APPROX 6.5 FT. TRY TO BREAK THE FALFALL WITH MY LEFT HAND, BUT THE WEIGHT OF MY BODY TOO STRONG. HIT THE GROUND AND FELT A SNAP TO MY LEFT HAND.