The influence of external ankle braces on subjective and objective parameters of performance in a sports-related agility course

With lateral ankle sprains being the most frequent sports-related injury, there is an evident demand for the preventive measures in active individuals with chronic ankle instability. Braces are commonly used for prevention and treatment of ankle injuries. Various investigations-mostly performed with healthy subjects-focused on this problem, yet they often compared only a few models or used only limited testing procedures. However, controversy exists whether braces affect sports performance. The purpose of the present study was to compare the effects of ten different ankle braces-one rigid, five semirigid, four soft models-in a comprehensive evaluation with multiple testing procedures in 34 subjects with self-reported chronic ankle instability. The multiple testing procedures evaluated objective performance-related parameters and subjective parameters related to comfort and stability. The subjects performed an agility course with maximal effort. The course included a vertical jump and a cutting maneuver, both on a force platform, a single leg hopping test on level and inclined plates, a combined straight and curve sprint and sidesteps. Three valid trials were measured and averaged for each brace and every subject. Subjective aspects were evaluated with a questionnaire about handling, perceived restrictions, support and comfort; it was completed after each brace was worn and tried. With regard to the objective parameters, no significant differences were found between the braces except for the rigid brace which showed decreased values for the vertical jump and longer times for the other tests compared to all other braces. The subjective evaluation of the braces revealed significant differences with respect to comfort and handling and therefore, permitted a distinction between semirigid and soft braces. Although significant differences between braces were found in subjective performance restriction, no significant differences were revealed in the objective evaluation. From that point of view, patients could choose a brace model according to their individual needs. A comfortable brace might have a positive influence on the athlete's state of mind although other aspects like the brace's stabilizing effect play an additional role and should also be taken into account for recommendation of braces.