
He had Polio all his presidency, but since disability was treated especially poorly in his time, they often would hide around it FDR had leg braces that could allow him to essentially lock his legs into place and “stand”. And in the public appearances where he “walked” - which was more of a hobble - he would often have Eleanor there walking beside him arms together to sorta mask he was actually reliant on her
He actually made a deal with the press since - in media circles - it was an open secret. All the pictures and footage they wanted as long as it was never of him walking or standing up/sitting down. You can look at archives, there’s very very few pictures of him in his wheelchair or of him hobbling, because any press photographer who tried to get a picture would literally have their camera snatched from their hands and stomped on by the secret service