RESUMEN
BACKGROUND Patients with chronic ankle instability (CAI) can present with abnormal gait. The purpose of this study was to evaluate plantar pressure distributions and posture balance during walking in unilateral CAI patients. MATERIAL AND METHODS We recruited 24 unilateral CAI patients and 24 healthy individuals; plantar pressure analysis was conducted using the Footscan® 3D pressure system. The following parameters were assessed and recorded: peak force/weight (PF/W), time to peak force (TPF), time to boundary (TTB), and COP velocity. The differences between the affected and unaffected side of the CAI group and control group were determined. Pearson correlation analysis and univariate analysis was used to investigate the correlation between plantar pressure parameters and related factors. RESULTS The comparison of PF/W showed that the plantar pressure of both sides in the CAI group were laterally distributed. The comparison of TPF, TTB, and COP velocity in different groups showed that the posture balance on the affected side of CAI patient was more impaired than the unaffected side and the control group. Male patients with CAI tend to have better posture balance than females, and a low CAIT score is correlated with poor posture balance. CONCLUSIONS The plantar pressure on both sides in unilateral CAI patients was laterally distributed and their balance function was impaired. It is necessary for CAI patients to receive functional training of both sides during rehabilitation, and plantar pressure analysis is promising for diagnosis and evaluation of CAI.