Take it from someone with two slipped discs in her spine — sitting at a desk all day is no walk in the park. In fact, sometimes my back is in so much pain that an actual walk in the park is no walk in the park, either. According to the American Chiropractic Association, half of all working Americans experience some form of back pain — including the youngest rung of the workforce. That means the “aching backs” we used to hear about from our parents now often apply to us, too. This is often a result of the poor posture that desk jobs cause us to develop. I know for a fact that I’m not the only 26-year-old with bad posture, but there aren’t quite as many people my age who also suffer from severe and chronic back pain. In addition to things like stretch, yoga, chiropractic treatment, physical therapy, and massage, I’ve tried a ton of different ergonomic chairs, quite a few back rests, seat cushions, balance balls, etc. to combat the constant stress on my back that’s caused by my slipped discs and generally terrible posture. After dumping way too much money into treatments that didn’t help much, I found one thing that has worked for me — a $6...