EE reported hurt his right knee 10/30/09 approx 12:00PM. EE reports he was walking across rocky ground , rock broke & he fell backwards. EE said when he fell he twisted right knee, it hurt at the time but didn't think much of it. 11/9/09 went to dr for check, put him in knee sleeve. 11/16/09 dr gave cortisone shot. No lost time, is working.