I found an indoor soccer shoe to wear, which for whatever reason, is much stiffer during the motion you make when you with the downward pedal stroke. Sneakers and running shoes flex when you do this, because when you run or walk, you want the shoe to give in this way. I can walk in the indoor soccer shoe but I wouldn't want to run in them (or play soccer in them for that matter). If you need to stick with the shoes you have, I would think a Dr. Shols type leather insole, the type made to compensate for falling arches, would stiffen up your regular shoes. Haven't ever tried it though.