My group fitness instructor is always nagging at us about where we put our hands during certain moves. Body weight squats and oblique dips - she insists that our hands should be behind our head for both, claiming it helps with form. In my years of doing Body Pump and GRIT, I'd never put my hands behind my head for either.
Is there any importance to this? I'm more comfortable with my hands in front of me for squats, and I really can't see that it matters one way or another for the oblique dips.