As SLF I had to fly once whilst on crutches and with my ankle still HEAVILY strapped up following a rugby injury. I was pre boarded and the cabin crew took great pains to ensure I was comfortable (seated right by the galley bulkhead for extra legroom) however I couldn't get my foot (left fyi) in properly as the rest of the passengers boarded. Approximately 60% managed to clout it
resulting in increasing pain whilst only 4 people said sorry.
It meant that I had to sit with my leg out in the aisle for most of the flight and the wonderful cabin crew not only made sure I was OK but managed to avoid me with all the carts they were using that day.