Yes such good advice about rehab therapy. An I feel like if he doesn’t want to go to rehabilitation that maybe he can purchase like some 2-5 pound weights , an start some sitting exercises with the weights. An he can find videos on line about Chair an bed exercises. I do the barbell exercises a chair exercises a get up more often through the day , an jus walk inside , around your house, if u don’t go outside much… every little bit helps .. we’ll that’s what in my mind. Good luck to you ! I’m on that same journey unfortunately.