Which one do you recommend? CD or duo bag?

pu1. If you are changing chairs because of a bad back, I recommend a disc chair, but it is also called a knilling chair. There are several kinds, so try searching on the Internet.

2017-11-18

OK

pu2. If you're going to use it at home, it's better to buy a gym ball than a chair.
It's much cheaper than a chair, but it's also good for your back disc.

2017-11-18

OK

pu3. I don't know if a duo bag is good for your back

2017-11-18

OK

pu4. I'm good at using CD but I'm not sure about the waist

2017-11-18

OK

pu5. I even used a Herman Miller chair that costs about 1.5 million won because of my waist, but I'm using a gym ball

2017-11-18

OK