Instruction: Given a question and the related document, predict if the question is answerable based on the information provided in the document. Output only yes or no.

Input:
Question: how easy is it to roll while sitting on it? have L-shaped work station, need to go back & forth without twisting.
Document: I can sit in this chair without having back, leg, or neck pain. I tried it at home and it was great, but didn't roll on the carpet. I use it at work and have a vinyl mat underneath so can easily roll between desk and computer. If I need to stretch my back, I can take the ball from the stand and use it for stretches, so it's dual purpose!
I've had no problems! I felt so much more stable than I did on my yoga ball, and because I am not fighting all the roll and directional changes, I feel I am more sensitive to slight changes in my posture on the chair, and quickly correct it (now without thought). If I become aware of changing my posture a lot, I take that as indication that I need to get up and walk around. I feel refreshed when I return to the ball.
I have been using this chair 5 days a week for 9 weeks. My old chair is handy and if I didn't like this one it would have been easy to go back. So far, I am exclusively using the ball chair. I am sitting on the chair as I write this review. My yoga instructor would be proud of my posture -- I was a horrible slouch for 20 years as a software engineer.I haven't had any problem with my ball falling though the chair.
Maybe I need to pump the ball up some more? Anyway, this is a fun way to sit and a good way to work on your posture without even realizing it! Pump the ball up way more than you think, plop in down on the frame and bounce away!
The wheels don't roll very well when I'm sitting on it so I lift my weight to roll it around ... I am average weight for my 5'5"" height. I sit straight up on it so don't use the back rest but it's nice to know it's there and I don't miss arm rests at all. The pump that comes with it is a little wimpy so if you don't want a work out inflating the ball I would suggest getting another pump.
I like the chair - the sitting position is great and the adjustable height was a feature not all of the chairs have. I could feel some muscles in my torso for the first couple of days, so that's proof that it's doing it's job. The down side is that the rollers don't swivel well, and since there's six of them, it takes quite a bit of effort to roll in the direction you want to go.
This chair is great therapy for people who sit at their desk all day. Just sitting on it relaxes and properly aligns your spine and shoulders. It does take getting used to. It operates best on a hard (not carpeted) surface. If you have a carpeted floor, you're better off without the frame. Just use a ball that is sized appropriate to your height for the same benefit. The frame is sturdy and easy to assemble.
Just as described, easy to put together, casters roll well. Gets a 4 because of lack of quality control - had to file off some metal burrs on the frame (those don't work well with inflatable balls).
This chair is the best desk chair ever. I have chronic back problems, this has all but eliminated my back pain. It makes your posture straight, no slouching allowed, without you realizing what is going on. The wheels roll nicely. I don't really use the back rest but I have had other people try it who do use the backrest. I would highly recommend this chair. I have moved my old desk chair to another room.
This chair is great. It's so easy to put together (and I hate putting together things) and the exercise ball that comes with it is much tougher feeling than most exercise balls. It feels nice and sturdy under your bum! Just be sure to give it 24 hours at 80% inflation (details included in instructions) so it can stretch out first. The back rest is totally great and provides support if you need to sit back.
Answer: yes