Your chiropractor will select the Orthotics best suited for you based on a variety of factors (lifestyle, health, age, weight, sex, etc.) He or she may recommend a style which includes the patent pending Gait Cycle System for shock absorption, support, and a propulsive "boost" with each step. And because most people wear at least two styles of shoes each day, your chiropractor may determine that a Combo (two pairs) would be best for your condition.