"Confined to a Wheelchair"
I've been volunteering with disabled kids. One kid I met while volunteering was this girl who's very delayed, possibly physically disabled as well. She has a wheelchair. I think it's accurate to think of her as confined to a wheelchair, the same way an 8 month old is confined to a stroller. That's because, like most 8 month olds, she can crawl really fast. However, she can't push her wheelchair independently.
Therefore, she has more freedom of mobility outside of her wheelchair. Her wheelchair is confining.