^ Maybe you just got dizzy. I did a bit of aikido too this year, but I had to stop due to the uni..
My teacher keeps telling us about a bit similar to that, something about internal power, my guess is that it's just being able to keep your abdomen stiff (and to execute the technique correctly, which is hard) so that you can correctly transfer the kinetic which will overpower your opponent. And yes, sometimes your wrists hurt like hell, but is fun, and I enjoyed it a lot more than judo.