Cortical Measures of Motor Planning and Balance Training in Patients With Chronic Ankle Instability

Abstract

Context Motor planning, a prerequisite for goal-driven movement, is a complex process that occurs in the cortex. Evidence has suggested that motor planning is altered in patients with chronic ankle instability (CAI). We know balance training can improve balance, but we do not know if it also improves motor planning. Such changes in cortical activity can be assessed using electroencephalography. Objective To evaluate changes in cortical measures of motor planning after balance training in patients with CAI. Design Controlled laboratory study. Setting Research laboratory. Patients or Other Participants Fifteen patients with CAI (age = 20.80 ± 2.37 years, height = 169.47 ± 7.95 cm, mass = 70.45 ± 19.25 kg). Intervention(s) A 4-week progression-based balance-training program. Main Outcome Measure(s) Motor planning was assessed via electroencephalography before a lateral-stepping task. We calculated event-related spectral perturbations in the θ (4–8 Hz), α (8–12 Hz), β (14–25 Hz), and γ (30–50 Hz) bands. The change in power (in decibels) was calculated in each band for the 500 milliseconds before the onset of the lateral-stepping movement. Additional outcomes were the Foot and Ankle Ability Measure (FAAM)–Activities of Daily Living and Sport subscales; the anterior-, posteromedial-, and posterolateral-reach directions of the Star Excursion Balance Test; and static balance. Patients completed 3 test sessions: baseline, 24- to 48-hour posttest, and 1-week posttest. Repeated-measures analyses of variance were used to assess changes over time. The α level was set at .05. Results The FAAM–Activities of Daily Living subscale score was improved at both posttests (P < .05), and the FAAM-Sport subscale score was improved at the 1-week posttest (P = .008). Balance was better in all 3 directions of the Star Excursion Balance Test at both posttest sessions (P < .001). After balance training, no differences were identified in cortical activity at either posttest session (P > .05). Conclusions No improvements were identified in electroencephalography measures of motor planning during lateral stepping in patients with CAI. Improved balance suggested that sensorimotor adaptations occurred, but they may not have transferred to the lateral-stepping task or they may have been mediated via other processes in patients with CAI.