Just this week, after reading an article, I have started to do DEEP squats. See here craigliebenson.com/is-it-wr...
I didn't think that I would be able to do it - but a few efforts each day has slowly gotten me to the point where I can do the squat ( with both heels firmly on the floor) and hold the position for a minute. If anything, my (still) slightly large stomach gets in the way - but as far as joints and muscles go, it seems OK .
Apparently it is good for you??? One thing is for sure, is that , provided you have loose clothing on , you can go into this position on a whim at any time and doing so slowly improves your ability to get there.