One was a midfoot reconstruction from a crush injury, another was the removal of one of the sesamoid bones due to damage caused by rheumatoid arthritis. I have a 28 pound aluminum frame bike. I slipped my feet in and they are flexible yet sturdy. So, if you are interested but think $100 is a bit to steep, I would strongly recommend Amazon Warehouse deals on either used-like new or used-good versions! ummm. I also walk approximately 7 miles everyday. UPDATE ordered a replacement pair and the right side got quiet within 24 hours of receiving them! I would never push 20 hours of use without charging. Works great in the US. Best part was the low price!