Employee was operating a mantrip on the E-track just inby E-24 cross over. When EE stood up to ensure that EE had clearance to maneuver into the switch EE struck the back of EE's hard hart on a roof strap which caused EE's head to move forward. EE's forehead contacted the radio compartment on the mantrip and caused a laceration to EE's forehead that required 5 sutures.