Comparison of the Effect of External Focus on Postural Control in Athletes with or without Chronic Ankle Instability while Standing on an Unstable Surface

BACKGROUND AND OBJECTIVE: Chronic ankle instability is a common injury in athletes that leads to postural control disorders. The aim of this study was to compare the effect of external focus of attention and postural task alone on center of pressure sway in athletes with chronic ankle instability and healthy athletes during dual task training. METHODS: This cross-sectional study was performed on 29 male volleyball athletes with a referral from a specialist and 29 healthy athletes matched with the affected group in terms of age, height and weight. Subjects in the two groups were on the balance board with single-leg and double-leg stance, standing in the center of the force plate for 60 seconds and performing postural tasks alone and with external focus. The degree of displacement of the pressure center was measured to investigate the variables of standard deviation of amplitude and mean velocity. FINDINGS: In double-leg stance, standard deviation of amplitude in medio-lateral (14.2±2.1) and anterior-posterior (16.7±3.3), mean velocity in medio-lateral (39.2±9.8) and anterior-posterior (40.7±6.1) directions in patients during external focus were significantly less than the standard deviation of amplitude in medio-lateral (12.2±1.5) and anterior-posterior (13.9±2.4), mean velocity in medio-lateral (46.2±13.1) and anterior-posterior (48.4±9.6) directions during the single task. In single-leg stance, standard deviation of amplitude in medio-lateral (16.1±2.1) and anterior-posterior (13.1±1.7), mean velocity in medio-lateral (42.2±13.3) and anterior-posterior (40.7±8.6) directions in patients during external focus were significantly less than the standard deviation of amplitude in medio-lateral (11.1±2.1) and anterior-posterior (17.4±3.3), mean velocity in medio-lateral (47.8±16.6) and anterior-posterior (55.2±17.4) directions during the single task. CONCLUSION: The results of the study showed that external focus task leads to distraction from postural control and reduces postural sway in athletes with chronic ankle instability