I am 37 years old and when I was young i too had pain in my knees and feet. I do believe this is from being under-suppressed. I have learned over the years that when my left knee starts to hurts about in the center of the joint it is time to take an extra dose. I used to run croos country and quite because the pain was so bad and after seeing 4 different orthopedics who could not find anything i had just decided I was going to have to live with it. I was not until my mid 20’s that I figured out it was my meds being off. I guess this is just one of the symptoms we learn to figure out how to live with.