Gaiam Balance Disc Wobble Cushion Stabil

Gaima has AWFUL practices. Let's start with the fact that I received a clearly used product that you are supposed to sit on. Bottom is worn, the inflation opening is scratched around the surface and the product arrived pretty heavily deflated. It seems pretty clear that somebody got the product, used it, didn't like it and returned it and Gaima then sent it to me. Extremely poor form. So, my product looks nothing like the picture because it arrive so deflated I could touch the top to the bottom. I pulled out my foot pump, attached the needle (which only by sheer persistence worked because I had to keep putting it back in the hose) and performed CPR on the pump for about 20 minutes. There must be another dimension houses within the ball because air was going out of the pump, it wasn't leaking out of the ball or the hose and the ball didn't inflate one bit. I chalked it up to being defective and tosses it back in the box with the idea in mind of returning it. Well, I bought the ball as part of a total-body physical therapy measure to both help me regain strength after my last surgery and to help me recover from my next surgery. I was farting around with some resistance bands I had and trying different exercises from different angles and I was having a rough time getting full range of motion on some quad and hip exercises because my legs were just a bit too long. I broke out the ball, plopped in on the chair and sat down. I'm not very heavy and I'm not very tall- 5'9" and 170 pounds. When I sat on the ball the air pressure caused by my weight caused it to raise in height several inches and straightened my back, extended my stomach and raised my knees so my thighs were parallel to the ground and my feet were flat. I instantly felt sore in my lower back and lower abdomen. It was working EXACTLY as it was supposed to. Curious, I then took it to my office chair, where I couldn't touch my heels to the ground unless I sat on the very front of the seat (which then causes me to slouch as my back rounds out to accommodate the downward slope of the seat) and puts pressure on my lower thighs (which hurts my knees because it causes my heels to hang). I plopped the ball down in my chair and sat on it. Again- spine goes straight, knees come up, thighs parallel to the ground, feet flat on the floor. Soreness in my lower back and lower core. Gaima's business practices aside, this thing works PERFECTLY. Give it an honest shot. I can't speak to how well it will work for much taller or shorter or much heavier people, but the ball I got is exactly the dimension I needed. Don't toss it before trying it, even if it looks lousy when you get it. Three stars because it works. Minus one for the condition it came in and the non-function of the inflation aspect and minus one for the fact Gaima clearly sent me a ball someone returned.