Does anyone use the Medela hands free pumping bra? Does it work?

I’m so tired of trying to hold these things in place for 20+ mins. Most of the time I don’t last that long because my back hurts soo bad. I assume that’s just causing a reduction in milk as well. But my back hurts soo bad

Does the bra work? I bought 2 from target but couldn’t get either zipped across my chest - need to buy a bigger size if it works?

Also where do you get good nursing bras? I got some from amazon and a plastic piece has popped out of the side and stabs me under my arm-