If I am younger than 12 OR very petite for my age OR have a very narrow foot does that change my size for the Infinite, Performance or the Alpha Shock?

Infinite and Performance Shock sizing may vary based on foot size and age. You may consider selecting one size smaller if: If you are younger than 11 years of age, are very petite, or have a very long/narrow foot but have a larger size of foot. For example: an 11 year old who wears a size 6 shoe would choose a size Small Infinite instead of a Medium (based on the size chart). A 16 year old who wears a size 6 shoe and has average leg and foot size would choose the recommended size Medium.