When buying computer chair, you can sit on it to feel whether it is comfortable. If the chair design is reasonable, you must feel more comfortable.
The chair back should be firm. When buying computer chair, you would notice that some chair back is loose and when getting close to the chair, you can hear the noise. If you are wise buyer, please not to buy such chair because it is easy to be damaged.
Try to shake the chair from left to right and then from right to left, if the chair structure is not stable, it is easy to be damaged.
Pay attention on the chair handrail. Put your hands on handrail to feel whether the height is suitable and comfortable.
If you want to buy rotating chair, you can try to rise or fall the chair to feel whether it is smooth during the lifting and down process.
Turn over the chair to check its hidden structure, if you notice there are some coarse parts in the hidden area and even some rust, it must be the poor quality chair.