AFTER ADJUSTING A BEARING UNIT ON PUMPING SYSTEMSEALING WATER PUMP EE WAS DISMOUNTING THE FLOAT WHICH WAS ABOUT 28"" FROM SLED TO GROUND. HE WAS HOLDING A 3/4"" COMBO WRENCH & CRESCENT WRENCH IN HIS RIGHT HAND, HOLDING ONTO THE HANDRAIL WITH HIS LEFT HAND. WHILE BACKING OFF THE PLATFORM HESTEPPED ON A 2 1/2"" ANGLE IRON BRACE & TRIED TO CATCH HIMSELF WITH HIS HAND & HURT HIS SHOULDER.