At about 1525 eastern time, a landing Waco UPF-7 collided with a Kitfox that was backtaxiing on the runway at Moraine Airpark. The pilot and two passengers in the Waco received minor injuries, while the pilot in the Kitfox was not injured. The Kitfox pilot said he landed in the grass next to runway 26. He then taxied east in the grass and looked down the runway and saw no traffic. He then announced on the CTAF that he was backtaxiing on runway 26, but when he entered the runway he was struck by the Waco, which was on its landing roll. The Waco was not equipped with a radio.