I had back surgery in 1988 and was totally bed bound for 2 weeks. When I was finally allowed out of bed, I couldn’t walk on my own. I needed a walker and a nurse to help, because my leg muscles had weakened due to inactivity. So if they’ve never been used then, realistically, there’s no way they’d be even getting out of bed let alone walking. Unless you can find a way to get around that somehow.