Sivan Health and Fitness Balance Ball Fit Chair Base with Ball & Pump

Update: After two weeks of use, I still like this Sivan balance ball chair with no back. I solved the sore bottom problem by sitting a little further back on the ball. Much more comfortable. I still have had no incidents of feeling like I am going to fall off. I keep all 4 wheels locked, and the surface of the ball is not slippery. I have the ball filled to 65 psi and it does not seem to have lost any air in two weeks.After reading many reviews, I selected this Sivan balance ball chair with no back. The company was very responsive to my request for a piece missing from the box with a broken seal. I suspect I got a chair that someone else returned, but the Sell Below Cost company offered the best price I found, were quickly and accurately responsive, and included an apology for the missing piece and an offer to help if there were any more problems. Love doing business with a company with that type of service and attitude. The original order was received quickly, and the replacement part followed quickly within a couple of days while the ball was sitting at room temp and getting the first fill of air. I love that all 4 wheels lock. At my age, it is critical to avoid falls, and I think 4 locks helps. I have not had any trouble with falling off or feeling like I might fall off. With the wheels locked, I am able to move around a little and reach where I need to reach with no extraordinary efforts. Initially, I did not put enough air in the ball. The low air was perfect for my height to the ground with 90 degree angles at the knees, but I felt too low for my office desk and felt none of the movement advantages others described. I added air from a compressor and used 65psi as my cutoff. The ball almost doubled in size! I like the way it sits much better, but it is too high and I use a stool or I exercise calves while not using a stool. I choose to use the ball higher because I feel the "balancing" effect is there with the extra air, but not with the lower air. The whole assembled chair is also light enough for me to pick it up and put it outdoors on my deck, my favorite place to work! My only complaint is that my 'bottom' gets sore, kind of like riding a new bicycle seat but more spread out. The soreness is only after I have been sitting awhile, and does not continue after I get up and move around. I am hoping the soreness goes away completely as I use the chair more often and for longer periods. Plus, the pain forces me to get up and take a break, which is a huge plus for circulation. I tend to forget the lengthy time stretch I am sitting, so forced breaks are a plus. I am taking the advice of others and attempting to gradually extend time on the ball. I have had no more back pain than I have in regular office chairs. I recommend this Sivan balance ball and chair base for economy, quality, and the exercise-while-sitting purposes for which it is intended. I doubt I will ever do other exercises on it, because of the chance of falling. I hope I can benefit from the balancing movements others have described while using it as a desk-work chair.

I am satisfied with this purchase. When I first pumped up the ball, I was worried it wouldn't be tall enough for me (5'7") but looks are deceiving. This has been the most comfortable solution to a desk configuration I've tried yet. I hate sitting in normal chairs, I've tried standing desks but still kept slouching. This chair is really helping train my core to become more stable on its own. The base is great too to keep the ball from rolling around and disturbing co-workers!The only complaint is in line with other reviews - the locks on the wheels lock when my feet hit them. It's a tad annoying, but worth it.

It was very easy to put together. The price is good. But it is just too short. I will give it a few days and fill the ball more but as of right now it is 2 or 3 inches too short. I may have to purchase a slightly bigger ball. I would not buy this again.addendum: I waited 3 days and inflated the ball more. It is amazing what happens when the ball is fully inflated. Now the height is perfect. So don't be afraid to go nuts and really inflate that stinker!

I got this to help with my posture post knee operation. I will be using this also to help lift my leg up and later to use as office chair. overall good for my 6'2 250lb frame. It does shrink a little over time and you do need to pump it up. I pumped to the max on day 1 and let it contract since I knew that it will due to (1) being new and (2) air contracts and expands on temperature. The ball that it came with is not the greatest, but is still decent and good for daily use.The only other con is that I tend to step on the wheel lock more often than want to. I guess that's user error...Update Jan 29, 2015. I have not used this ball much since the initial review other than prompting my leg up and occasional hamstring pulls as I was still recovering. I returned to work today and sat through half a day when I noticed that wheels were not moving. I thought they were locked but turns out that the frame caved in making the wheel lock in. Amazon is not accepting exchange or returns. The unit did not last one solid day. 3 of the 4 sides caved in as it's hollow in the middle of the construction.

The product works as described and is fairly easy to assemble. It has a horribly annoying design flaw though; the locks on the wheels are on top, so it is impossible not to constantly accidentally lock the wheels. Needless to say, this is very annoying. I wouldn't recommend this to anyone who wants a mobile chair that can move around a bit. The ball is fine.

*****FOR THOSE PURCHASING FOR OFFICE/BUSINESS USE*******I did not purchase this ball to workout with, I purchased it because I sit in a chair all day at work and I have lower and upper back pain due to an auto accident. Putting it together took me about 10 minutes and was very simple. No extra parts!!!!!! Sitting in a chair all day was continuing to hurt my back and created bad posture and I needed a fix. I tried adjusting my chair at work and standing etc and I just could not find a way to get my back pain to go away while sitting at work. Well I found the solution with this chair. It almost forces me to sit up straight and does it comfortably and that is the main thing. I am finally comforatable while sitting all day at work, my back does not hurt at work and I feel better overall. Living with back pain and not taking any meds because I am a diabetic can be difficult but this chair has helped me tremendously and I am very grateful.