Back pain from treadmill?

Amanda82691

Ok so since mid December I have been getting more into running. I have went out and made sure I got proper shoes, and I even bought a treadmill for when its really cold and bad weather out. I love running outside more then the treadmill but where I live that isn't always doable. When I run outside I never have back pain that day or any day after. But lately when I started running on my treadmill I have been getting horrible back pain. And yesterday it was so bad I could barely move. I would say it has to do with my running form, but why would I have no back pain when running outside, on sidewalks, trails ect but then have it when I run on the treadmill? I know none of you are doctors but any ideas?