Some people have such high tone in their legs that their legs automatically cross or "scissor." Adapted chairs like this both help keep you from sliding out of the chair and help keep your legs apart so you don't get decubiti from having the skin of your legs rub together all day and create painful ulcers. If you can imagine yawning and stretching your legs and arms, when you are at your most stretched out and your toes are pointing - that is how the limbs of people with spastic cerebral palsy are all the time. The brain sends a constant impulse to increase the tension or tone in your limbs, and so your limbs are never at rest - they are always hyper-extending, but your legs would be "scissored" and cross each other all day with no break. Very exhausting to the body, very stressful for your self-concept and how others see you when you have no control over the process, and sometimes painful, especially when skin breakdown occurs. Intrathecal baclofen therapy (a muscle relaxant is implanted in a device in the body and provides timed release of medication directly into the nervous system) is one of the coolest inventions in the world because it is one of the few ways in which your extremities finally get some break from the constant tension.
Truth is, y'all, you gotta be tough as nails to have a severe disability - it's often hard work just getting out of bed every day.
I believe this is one of the early tech gadgets where the top would have some information and you could choose the correct answer from the side - possibly an early communication board.
It's just another adapted chair. Before they had PVC pipes and lightweight metals they used wood when they were making adaptive equipment because otherwise it was too heavy to move and it was difficult to self-propel or rock in an all-steel chair or rocker. In the late 60s through mid 80s a large number of adaptive chairs and other pieces of adaptive equipment had sections made of lightweight wooden boards or pressboard and the seats/sides had heavy duty padded vinyl so they could be easily wiped down and washed. It is much easier to work with a 200-pound person in a 20-pound chair than a 200-pound person in a 120-pound chair. Also it was a heck of a chore trying to move a heavy metal chair with someone in it across crowded fair grounds and go over electric cords and such or use a wheelchair trying to take a short jaunt to the store before the ADA mandated sidewalks with cut-away curbs and worry that you might tip over trying to get on or off a sidewalk - BEFORE cell phones were available so's you could call someone for help.
We LOVED that equipment - it was much easier to work with, more comfortable for the people who used it, easier to move, easier to clean, and looked a whole lot better than most of those iron maiden papa-sized chairs.