Sitting at the wheel hurts my hips

Hello the forum,

I recently got my own wheel and am as happy as a girl can be. When I have time I find that I can easily spend 8 hours at my wheel. The only problem is, after several hours my hips start to ache, after 8 hours they HURT. I am getting up and stretching between pots and I take breaks. I'm careful about how I hold my hands and arms to avoid repetitive strain injury, but I don't know what to do about my hips.

Does anyone else experience this? Any hints or suggestions would be most appreciated.

Thank you in advance!