PERCEPTUAL AND BIOMECHANICAL VARIABLES FOR RUNNING IN IDENTICAL SHOE CONSTRUCTIONS WITH VARYING MIDSOLE HARDNESS

Objective. Perceptual ratings of mechanical variables were compared wi th biomechanical variables that are related to running injuries. Desig n. Eight identical running shoes with a relatively close range of mids ole hardness were used. Ground reaction force (GRF), in-shoe pressure distribution and rearfoot motion were measured during running. Percept ual ratings were obtained after the running trials. Background. Previo us studies reported high correlations between cushioning perception an d biomechanical variables for shoes that featured large differences in midsole hardness. Methods. A 15-point categorical rating scale was us ed to judge impact severity, pressure magnitude and rearfoot motion in running. Rating scores were compared with biomechanical variables (GR F, pressure distribution and pronation values) using regression analys es. Results. Regression analyses revealed high relations between diffe rent biomechanical variables and the perception scores. The best relat ion to perception was analysed for the median power frequency of the v ertical GRF (r(2) = 0.97). A negative correlation (r(2) = 0.54) betwee n the first impact of GRF and the perception of impact severity could be revealed. Conclusion. The present study suggests that the body's se nsory system seems to differentiate well between impacts of different frequency content. Based on perceptual abilities, subjects adapt their running style to avoid high heel impacts. Relevance Perception of inj ury-related variables is an important issue in the discussion of the e tiology of sports injuries. The protection and prevention ability of t he human body is restricted, if runners are not able to perceive the i ntensity of factors that are related to running injuries. (C) 1997 Els evier Science Ltd.