THE INFLUENCE OF HEEL LIFT MANIPULATION ON ACHILLES-TENDON LOADING INRUNNING

In this study, a modeling method was developed to estimate Achilles te ndon forces in running. Owing to the common use of heel lift devices i n the treatment of Achilles tendon injury, we investigated the influen ce of increased heel lift on Achilles tendon loading. The hypothesis w as that heel lift manipulation can influence maximum Achilles tendon f orce. Responses to heel lift variation were found to differ among 3 el ite runners demonstrating distinct running styles. A rearfoot and a mi dfoot striker demonstrated significant increases in maximum Achilles t endon force with increased heel lift, whereas a forefoot striker demon strated no changes in maximum Achilles tendon force values with heel l ift manipulation (p < .05). Analysis of the factors contributing to th e observed changes in maximum Achilles tendon force highlighted the in fluence of the moment arm of ground reaction force and the moment arm of the Achilles tendon about the ankle joint center. The finding that increased heel lift may increase maximum Achilles tendon force suggest s that caution is advised in the routine use of this intervention The different responses to heel lift increase between subjects highlight t he importance of classifying subjects based on running style.