One of my co-workers had a kneeling chair and was able to sit in her chair for a long period of time without issue. I should've asked her where she got her chair before I purchased this one. I can only sit in it for 15-20 min before I'm in pain. It definitely helps with posture, but there's too much pressure on the knee caps. When I adjust to relive the pressure, I get bruises on my shins. Unfortunately, I cannot return the chair. I recommend going someplace where you can try the chairs 1st before ordering.