Awky duck, awky duck,
Broke me leg an I can't get up.
Awky duck, awky duck,
Broke me leg an I can't get up

Dad was always singing, and any event in our lives could trigger a song (often from his own childhood). So in reposnse to the exaggerated limping we would do after any fall or slight knock, might give him a chance to try to make us laugh (and so forget to limp, or change leg or whatever) by singing this song. The tune is the Cuckoo Dance (Laurel & Hardy's theme tune) and there's a recording of Ewan Macoll singing the lyrics above here:

http://research.culturalequity.org/get-audio-detailed-recording.do?recordingId=7115