Thanks, LR. No, it definitely wasn't that, it was rudder movement. Does anyone else remember being told to do this?
I know it doesn't make sense, but I'm fairly sure that I did give it a bit of opposite rudder in banked turns, both on the flights with instructor and on my solos. I'm still here to tell the tale, so obviously it didn't do much harm, but I'd love to know what was the rationale behind it!