loop some bones

Hello. is there any simple way to loop some bone animations? lets say i have a character walking, and i want to loop the leggs but not the body, so i can do whatever i want with the body, but if i want to change the walking style then i only have to edit one keyframe instead of editing it then copypaste it many times.

For walk cycle, you create one cycle action in Dope Sheet. That can be placed in NLA editor and repeated.