Balance deficits in recreational athletes with chronic ankle instability.

Context Deficits in static and dynamic stability during single-leg stance have been noted in individuals with chronic ankle instability (CAI), but few investigators have tested subjects for subtle deficits in dynamic balance. Subtle deficits in dynamic balance during a double-leg stance may reveal changes in the sensorimotor system because of CAI. Objective To use a standardized tibial nerve stimulation as a perturbation to test for dynamic balance deficits between a group of recreational athletes with CAI and a group of recreational athletes with stable ankles. Design Case-control study. Setting Laboratory. Patients or other participants Twenty recreational athletes with CAI and 20 recreational athletes with stable ankles. Intervention(s) Balance deficits were assessed for each subject during static and dynamic trials. Main outcome measure(s) Time to stabilization and center-of-pressure excursion path length, velocity, and area from ground reaction forces during double-leg stance were collected through a forceplate. We used an accelerometer to measure tibial acceleration. Data were collected during static stance and during a bilateral perturbation using maximal motor neuron recruitment elicited by electric stimulation of the tibial nerve. Results Only time to stabilization in the anterior-posterior direction was significantly different between groups ( P = .04), with the CAI group taking longer to return to a stable range of ground reaction forces. We found no other differences in stability measures between the groups. Conclusions Dynamic balance in double-leg stance as measured by time to stabilization appears to be affected in individuals with CAI. Deficits in the response to external perturbation may indicate subtle central sensorimotor changes.