Why are my shoes showing wrinkles?
One of the main benefits of our technology is how it interacts with the foam. Though we do our best to prevent them, some wrinkles are inevitable and may result even during manufacturing. The style you have is from our higher performance product line. For our higher performance styles, we designed our technology to be closer to the edge of the foam which helps enhance its ability to hug your heels during more demanding activities. A by-product, however, is the potential for more wrinkles on the surface of the midsole foam.
You can see an animated graphic example of how our technology is designed to flex with the foam here: Technology. In the animation, you can see the vertical wall that sets inside the foam and flexes against the foam.
Though we try our best to reduce any wrinkling in our designs, this is just the nature of foam as it's compressed with every step and is part of normal wear and tear.
Don't worry, any wrinkles are not due to failure or break-down of the foam. It's simply the result of the KURUSOLE technology moving and cupping your heels to give you maximum comfort.