Do you remember the movie Princess Diaries? Do you remember when the Queen showed the Princess the 'fake' way of riding sidesaddle and there is a wooden leg looped over the leaping head? Well, ever since then I have tried to find any historical information about that and have come up EMPTY!
However, during my search, I did come across this very interesting document showing how someone with a prosthetic leg could ride aside!!! Double click to enlarge the picture so you can see the details! The drawing seems to show how someone with a left leg dismemberment could ride, while the photos show an idea for someone with a right leg disability.