When I was recovering from a knee injury I much prefered using crutches in the parks. The first 2 times, we rented a wheelchair and brought that. I had to have the kind where your leg sticks out in front of you. I lost count of all the people that walked into my bad leg, it's like they don't even see you in a wheelchair. I started using the crutches the third trip and it was amazing the difference. People never ran into me and always made room for me to get by and were much more considerate in general. I suggest if you're proficent with the crutches to just use them in the parks and save a lot of stupid guests running into you. Just make sure you stop at guest relations and get a GAC. A lot of the turnstyles are much too narrow for crutches at WDW.