Center of pressure during stance and gait in subjects with or without persistent complaints after a lateral ankle sprain

• We compare patients with and without persistent complaints after an ankle sprain.
• Patients with persistent complaints have a more lateral located loading response.
• Postural sway while standing with eyes open did not differ between groups.

Study aimTo investigate differences in the center of pressure (COP) during gait and single leg stance between subjects with persistent complaints (PC) and without persistent complaints (NPC) after a lateral ankle sprain.Methods44 patients who consulted the general practitioner, 6–12 months prior to inclusion, with a lateral ankle sprain were included for the current study purpose. Using a 7-point Likert scale patients were divided into the PC or NPC group. All subjects filled out an online questionnaire, walked along a walkway and performed a single leg stance, both on the RSscan. Primary outcomes included the COP displacement, range and percentage used in mediolateral and anterioposterior direction.ResultsThere was a trend (p < 0.05) towards a more medially COP trajectory during walking at 34–46% and 83–96% and more anteriorly at 21–31% and 91–100% of the stance phase in the PC group compared to NPC group. Additionally, the COP was more laterally located in the sprained leg compared to the non-sprained leg in the PC group in the loading response phase (p < 0.05). An interaction was found for the percentage of anterior–posterior range used in single leg stance without vision.ConclusionThe COP trajectory discriminates between patients with PC and NPC. This indicates that roll off during gait might play an important role in the recovery of patients after a lateral ankle sprain and could be used to monitor treatment.