Miner was exiting the D7 Dozer he was operating, from the leftside of equipment. The Miner proceeded to step down from Dozer, when his left knee twisted. On 01/29/08, EE injured his left knee, but EE did not request any time off. At this time no lost time injury was reported, but on 2/19/08 at the request of his doctor, EE did not report to work.