The crew was slipping and cutting drilling line as per ton-mile program and had finished cutting the drilling line. While re-attaching the drilling line to the drawworks drum, the motorman was standing on the equalizer bar for the braking system and was pushing the drilling line under the drum to a floorman. The floorman was reaching over the top of the drum to pull the drilling line to the drilling line anchor hole in the drum. The motorman’s foot slipped off the equalizer bar and went down between the brake shaft and cam for the crown block safety device. At the same time, the floorman who was reaching over the top of the drum, inadvertently bumped the crown block safety device. This activated the braking system and caught the motorman’s foot between the brake bar and the cam.