this office stool is the best thing that' s happened for my back - at first you have to use it for short periods until your back gets stronger but then it is so comfortable and good for posture. Like riding horseback. The only thing it needs is a softer seat.  I am going to add a layer of foam to mine.  I had shoulder and neck tightness from sitting in a regular chair at the computer.  Now I sit straight, my back feels stronger and my posture is improved overall. I used to have trouble standing for a long period or sitting in bleachers.  This stool has helped my back so that I can do those things easily now. I think that when we sit for long periods with a back rest our muscles get weaker..  this stool has been a very good investment for me.