Comparison of Plantar Pressure Between Patients With Severe Chronic Lateral Ankle Instability and Healthy Subjects

Background: The biomechanical pathophysiology of chronic lateral ankle instability (CLAI) is not fully understood. Planter pressure is susceptible to subtle changes in foot and ankle movement and could be used to detect CLAI. Therefore, this study aimed to compare plantar pressure between patients with CLAI and healthy subjects.Methods: Eighteen patients with CLAI who were scheduled for anterolateral ligament repair (9 women and 9 men) and 100 healthy subjects (50 women and 50 men) were included. Using an in-shoe pressure sensor system with ten plantar pressure sensors, the plantar pressure was recorded at a sampling rate of 200 Hz while walking. Analyses were adjusted for body mass index and gait speed.Results: Patients with CLAI had a significantly lower peak pressure on the hallux and toes than did healthy subjects. However, patients with CLAI had a significantly higher peak pressure on the medial aspect of the foot than did healthy subjects. Conclusions: The planter pressure distribution significantly differed between patients with CLAI and healthy subjects. The difference could have been due to a compensatory mechanism to prevent ankle instability. These findings could be used to elucidate the biomechanical pathophysiology of CLAI.