A simple and effective way to increase the stability of both running shoes and the rearfoot is to fabricate a heel counter stabilizer. Heel contact is the first aspect of stance phase during gait and is an extremely critical time for the running foot. The runner generally lands on the outside portion of the heel and rolls to a level position. Depending upon the runner's anatomical and functional variations, the foot may not roll far enough (excessive supination), or roll too far (excessive pronation). These actions tend to breakdown the rear of the running shoe, and rearfoot control is lost. Rearfoot control is of utmost importance for proper shoe wear, sound running mechanics, and injury prevention. The heel counter is responsible for rearfoot stability. This is located in the rear of the shoe under the foxing, which extends laterally and medially to the corresponding longitudinal arch. It is typically made of cardboard or a type of plastic. If this is broken down, calcaneal valgus or varus could result, leading to a multitude of potential lower extremity injuries (i.e., plantar fascitis, posterior tibialis tendinitis, patellofemoral dysfunction), as well as the investment loss of the shoes. The technique described will give additional support to the heel counter. It can be used to prevent the counter from breaking down, or to correct an already destroyed counter. However, discretion should be used as not all heel counters are salvageable. The procedure is a nonconsuming endeavor utilizing materials common to most physical therapy departments, training rooms, or private clinics. J Orthop Sports Phys Ther 1983;5(2):82-83.