I was tremendously sore back especially cervical and lumbar level, I went to almost every month osteopath to make me released. I bought the cushion for my work at the beginning of using the feeling is strange, we must find balance and be straight, not very easy. I felt after several hours of use a few different pain (stretching feel like doing sports). To my surprise I have much less pain ... and especially since the purchase of the cushion I not go to the osteopath. Now I can no longer past when I stay long sitting.