SLIP OR FALL OF PERSON at Lafarge North America
As employee was using a high pressure fire hose to clean under the main rock conveyor, he started to stand up. As he was starting to stand up, the water pressure increased causing him to lose his balance. He caught himself from falling backwards by extending his right arm behind him. When he did this, he heard a popping noise that sounded like knuckles cracking.
U.S. Mine Safety and Health Administration