Sounds like flexibility/stretching/yoga/YRG will pay much bigger dividends for this person than a barbell ever will at this point in his life. Not that he can't or shouldn't lift, but it's like taking a car that's been on blocks for years and trying to race it. He needs a lot of prep work.
All weighted exercises for this guy should be light, stressing full ROM. Pick exercises that challenge his ROM without breaking down his form (or what form he does have).
The body naturally contracts as we age, we must do what we can to fight this, that's flexibility. He sure doesn't need SS at this point in his life.