Internal Mechanical Work and Maximum Subtalar Joint Pronation in different gradients

Abstract

Introduction: Some authors have described the importance of physiological intensity in the behavior of the biomechanical aspects of running (for example, subtalar pronation), but the complex relationships among these variables are not yet well understood. Objective: The present study investigated the influence of positive gradients on internal mechanical work (W_int) and maximum subtalar pronation at a submaximal running speed. Methods: Sixteen male, trained long-distance runners (age: 29 ± 7 yr; stature: 1.72 ± 0.07 m; body mass: 72.1 ± 10.6 kg) performed four running economy tests (gradients: +1%, +5%, +10% and +15%, respectively) of four minutes at a same submaximal running speed in order to quantify the maximum values of subtalar pronation and predict the W_int values. Data were analyzed using descriptive statistic, Student’s T-test and one-way repeated-measures (ANOVA) along with the Statistical Package for the Social Sciences (SPSS) version 20.0. Results: W_int increased according to gradient (p < 0.05). However, no significant differences were observed in maximum values of maximum subtalar pronation corresponding to each gradient. Conclusion: Results show that the maximum subtalar pronation during submaximal running depends of the speed rather than intensity of effort.