Oscillation of plantar pressure center in athletes and non-athletes with and without ankle sprains☆

OBJECTIVE To assess whether there is any difference in the oscillation of the plantar pressure center in single-leg stance between athletes and non-athletes with and without ankle sprains. METHODS 54 volunteers performed four static assessments and one dynamic assessment while standing on one foot on a baropodometer, barefoot, for 10 s in each test. The variables of area (cm(2)), distance (cm), anteroposterior oscillation (cm), mediolateral oscillation (cm) and mean velocity (cm/s) were analyzed. The items "other symptoms" and "sports and recreation" of the subjective Foot and Ankle Outcome Score (FAOS) questionnaire were applied. For the statistical analysis, repeated-measurement ANOVA (ANOVA-MR), multivariate ANOVA (MANOVA), Tukey's post hoc test and partial eta squared were used. RESULTS ANOVA-MR revealed differences regarding distance, with major effects for eyes (p < 0.001), knees (p < 0.001), group (p < 0.05) and the interaction between eyes and knees (p < 0.05); and regarding mean velocity with major effects for eyes (p < 0.001), knees (p < 0.001) (p < 0.05), group (p < 0.05) and the interaction between eyes and knees (p < 0.05). MANOVA revealed main group effects for distance (p < 0.05), anteroposterior oscillation (p < 0.05) and mean velocity (p < 0.05). In the FAOS questionnaire, there were no differences: "other symptoms", p > 0.05; and "sport and recreation", p > 0.05. CONCLUSION Athletes present higher mean velocity of oscillation of plantar pressure center and generally do not have differences in oscillation amplitude in the sagittal and coronal planes, in comparison with non-athletes.