I recently attended a 7 day Chan retreat and was working on vipassina. One of the instructions given was to not move at all during a sit. I had heard this before and passed it off with "it doesn't matter how I'm sitting, just as long as I'm noting, yadda yadda yadda, mind mind mind," but gave it a try this retreat. What I found was my equanimity -- and I'm referring to the enlightenment factor; no comments on maps here -- increased from the practice.
Moving, I found, was typically done to alleviate some undesirable state: my back hurts and I don't like it, my breathing could be better optimized if I move forward, oh no I'm going to drool on myself and I don't like that, etc.. Contained in the movement was a subtle rejection of whatever had arisen and a coin was removed from the jar of equanimity.
I'm not suggesting you cultivate a drooling habit, but maybe let it flow someday and enjoy the drool. That attitude helped me get out of some dissatisfied times. Sometimes it felt like a gentle austerity (read, not clenching), other times like a winner attitude of 'yeah, I like everything.'
Hope this helps.
Jeremy
