Knebbled
This is the word that my (then) 4 year old daughter told me she had done to herself when she hurt her leg . . . 'Dad (she said crying) . . . I've knebbled myself!' - This word is now commonly used in our household - and is spreading through the local village primary school.
I fell over a tent guy rope and knebbled my ankle. I fell and knebbled my arm . . . .