A new method for quantifying pronation in overpronating and normal runners

Previous studies investigating motion of the ankle joint complex (AJC) and its relationship to chronic long-distance running injuries have quantified motion relative to a neutral position. No investigators have examined pronation during running relative to a total range of motion of the AJC. This investigation developed a method to quantify pronation during running from a total range of motion of the AJC. A six degree of freedom fixture quantified an active range of motion of the AJC. Common methods were used to obtain kinematic data of the AJC from running as a function of time. A method was developed to directly relate the range of motion data to the kinematic data. Fourteen overpronating and 10 normal runners were tested. Angular variables describing ranges of motion and maximum values were determined for each group, and an unpaired t-test was used to test for significant differences (P < 0.05). Results indicated overpronators had maximum eversion and abduction values during running that were significantly different from the normal runners. When measured from a neutral position no clear testable hypothesis was evident to identify runners predisposed to injury. When measured relative to the end ranges of motion a clear testable hypothesis was apparent. This method could be used to prospectively test the hypothesis.