I have been diagnosed with cartilage damage and arthritis in both knees – most evenings were spent with my legs up, knees on ice. I have worn my Happy Feet for the 4 days that I have worked. My knees don’t hurt, there is still a spring in my step and I am active when I get home. I cannot tell you how thrilled I am – my golf game is about 8 strokes better than it was last summer. I have been singing the praises of my Happy Feet to all who will listen. I am ever grateful for your product.