WENT TO SHUT GENERATOR OFF - 2 STEP PLATFORM GENERATOR. ON SECOND STEP, FEET SLIPPED AND FELL ON LEFT SIDE ON THE PIPE THAT RUNS ALONG THE DECK. CONTINUED WORKING UNTIL 2:00 PM WAS HOME BY 2:3 0 PM. LAID DOWN FROM 2:30 TO 3:00 PM. FELT SOMETHING POP. CALLED WIFE AT WORK. SHE CAME HOME AND SHE AND MY SON IN LAW TOOK ME TO EMERGENCY ROOM. TOOK X-RAYS. GAVE MEDICATION & SENT ME HOME.