A head rest might even appear.

The seat belts will attach to the rear spar above the seat and come through the frame at the top.

You are probably saying, "I've seen something like this before."

It's a expensive piece of medical equipment. I bought this side walker at a garage sale for a few bucks. All I had to do was remove the excess hardware and trim it to fit, flatted the lower ends and bolt it to the frame.