Now I need a new back

For the second time in 3 weeks my back decided to go out on me. The first time was just getting out of bed. The second time was while trying to clean up after the dog. Nothing very strenuous, I just happened to move the wrong way. The second time only allowed me to sit for 15 minutes or so at a time. I must find everywhere I sit that promotes bad posture and get rid of it. I’m thinking the first place is my chair at work. I spend a majority of my time in that chair and I think it may be part of my current back situation. Now all I have to do is find a good office chair.

Any suggestions?