I bought this for my mom for a recent holiday. She was getting back into her exercise routine, and a ball was at the top of her list. I went to Olympia Sports and found this 55 centimeter (22 inches approximately) ball. It was perfect for her since it was for people 5'4" and under. She's 5'3". Plus, I knew she'd like the girly color.
When the time came, she unwrapped my gift and took the deflated ball out of the box. Inside there were instructions and a pump. She excitedly put the pump together, but when she tried to put the end of it into the ball, it wouldn't fit. Frustrated, she decided she would just go back to Olympia and have someone there blow up the ball. They were able to blow up the ball at Olympia with another pump.
They said that the pump that came with the ball was defective. Once the ball was blown up, everything was fine and my mom was thrilled. She uses it to balance on while looking at paperwork. This helps her posture and her core. Some other exercises she does with it are arm exercises with her legs stabilized on the ball. She prefers having her legs elevated rather than leaving them on the floor. Similarly, she balances her legs on the ball, with her back on the floor, while she does crunches. Here's an exercise she does that she believes helps her hips and back: with her legs on top of the ball, her feet crossed, and her back on the floor, she moves the ball back and forth. Also, she loves just bouncing up and down on the ball because she thinks it's fun.
With these stability balls, the possibilities are endless. I borrow hers sometimes and just lay on it, to stretch my sore back. I think it was a good gift. My only complaint with it was with the pump.