I feel your pain! The shoes I bought in nursing school were absolutely horrible on my feet, especially in the later semesters when our clinical days lengthened. I experienced relief of knee pain more so when I began to wear compression stockings, and you can also look up exercises to strengthen your inner and outer thigh muscles and hamstrings. I am working on a year wearing my first pair of Danskos; they took a while to break in but I love how the recessed heel keeps your back in alignment and how they are easy to wipe down after a messy shift. They are also pretty readily available, I have even begun to see them in department stores. Hope you get some relief!