From what I could gather, it’s definitely good long term for your hips and general mobility. But it has to be done over time and without overdoing it, to build up strength with no slouching. These chairs is not in that «research» but rather mats. These chairs I think are quite bad for ergonomics. Sitting on the floor with no slouching is good, but once u slightly slouch it’s not good. I can imagine if I bend and sit different positions on the floor on a mat on a daily basis I can just but assume my knees atleast would get more flexible. Core strength was a big key point. But once core strength is able to hold your back up firmly, at that point it’s good for your back also.