Mike Logan wrote:
take a good look at the alignment in your legs
Couldn't put it better myself!
That is possibly the best thing you can do for yourself regarding any part of your body. When I was 14 I dislocated my kneecap while taking a particularly tricky pirouette in ballet class (that was the longest month of my life. I remember coming to Aikido to watch with a very sad look on my face). That is what led me to start taking Pilates lesions. The major concept is to work on aligning your body so that it works the way it was intended. You have to constantly watch your knees to make sure you are not bending past a 90-degree angle or beyond your toes. This is also applied all over the body alleviating sore lower backs, necks, bad posture, tense shoulders… you name it. It has been 4 years since I hurt my knee and started taking Pilates. This system of taking care of your body has since become second nature to me. Four years ago I was having trouble with seza and knee walking but now I have no problem.
Another idea to help your knees is to adapt a new style of ukemi. Many dojos practice this already, but in mine we are just beginning to learn what we call Donovan Weight ukemi. According to my teachers, it saves your knees a lot more than our traditional style.
And yes I did wear a knee brace for almost two years (I was so embarrassed by it). It was just a soft brace with a foam circle around it. It helped me keep my kneecaps from moving during Aikido class. I only stopped wearing one after I became good enough at the Pilates method to allow my own muscles to hold my knees in place. I would recommend wearing a brace for a quick relief of knee problems, but Pilates is a long-term training that will yield great results.
Good luck to everyone with those nasty knee problems