EMPLOYEE WAS WORKING ONT EH MUFFLER OF A PETER BUILT TRACTOR. HE AHD TH EPASSENGER SIDE DOOR OPEN AND STANDING IN THE DOOR WAY PUTTING THE TOP CLAMP ON. HE STARTED TO GET DOWN WHEN A RUBBER BOOT FROM INSIDE THE CAB FELL DOWN UNDER HIS FEET CAUSING HIM TO TRIP AND FALL TO THE GROUND. HE SPRAINE DHIS RIGHT ANKLE, LANDED ON HIS LEFT BUTTOCK AND BROKE HIS LEFT WRIST.