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.