Semi-seriously, a fully or partially automated "exercise" machine could be useful for folks with limited disability, just for keeping the joints and muscles from becoming rigid. As long as the design was safe enough. The tricky bit is eliminating pinch points, scissor points, etc., places where a misplaced limb could be injured.

As my mom's dementia worsened she would not exercise, at all. Besides the apathy that often accompanies dementia, her balance was worse and with chronic pain from arthritis and other problems she resisted physical therapy.

Unfortunately as she got older she lost mobility from being immobile for far too long. She ended up dying of pneumonia aggravated by immobility.

But a machine that could move the body around, preferably in graduated response to user input, could be useful for folks with certain disabilities.