Johnny Herbert is pretty badly disabled, but I don't think he's been mentioned. He damaged his legs badly in his Foitek precipitated Brands crash, and made a mostly good recovery, but it's left him with badly disabled feet & ankles. There's a lot of speculation about how good he could have been without the Brands injuries, but although undoubtedly significantly handicapped (you should see the poor guy walk!), he got good results including 3 F1 GP wins before retiring. I admired him at the time, and after reading his auto (?) biography, I've admired him even more.
Johnny's foot injuries would have been enough to force retirement in many cases, but Nelson Piquet did OK after shattering both ankles, they're easier to overcome than upper leg ones, which have ended the competitive careers of more than a few, Graham Hill and Jacques Lafitte are two at a high level that come to mind. Without looking it up, the only top driver who seemed largely unaffected after recovering from a badly broken femur was Rudolph Carraciola, though racing in his era was rather different from today's in many ways.
Some have mentioned having a short leg as a handicap, but if that was Bruce McLaren's only physical problem, I can't see that bothering him too much in a car, as his results testify. Many other have raced around similar problems, Graham Hill was another. With a properly altered shoe, which oddly some people disabled in this way won't wear, surely Bruce could have walked fairly normally?
EDIT. Someone has questioned the two apparently contradictory references to Graham Hill. To explain better to anyone confused, Graham's shortened leg was the result of a motor bike crash long before he raced cars, and it didn't seem to bother him much, as all his GP wins will prove. The disabilities that resulted from his much later Watkins Glen crash were very different, involving shattered knee joints and more. He made a surprisingly good recovery, up to a point, but he was never quite the same driver afterwards. Upper leg injuries again you see, very rarely recovered from 100%.
Edited by kayemod, 10 August 2017 - 10:41.