Fear-of-falls report during motor imagery and its impact on postural control in healthy young individuals

Abstract

Introduction: Motor imagery (MI) has been used in investigations regarding the cognitive features of postural control. During MI the postural sway increases compared with control conditions. However, there were no report about how affective features of postural control could contribute for MI effects on postural sway. Fear-of-falls, that also affects postural sway, could be a potential link between cognitive-postural processes. Objective: To investigate the association between fear-of-falls, MI abilities and postural sway. Methods: Twenty-five young adults (11 males) were evaluated, being asked to remain standing upon a force platform, with their eyes closed (control task), execute several times a plantar flexion movement (execution task) and imagined this same movement (kinesthetic imagery task). Each task was performed once for 45s. Postural sways were assessed and expressed as global directional stability index (DSIG). Participants were classified in a no-fear-of-falls (N=11) and with-fear-of-falls (N=14) groups, according to self-report during MI. The intensity of somatomotora sensation during MI was assessed with a 5-point scale. Results: Between-group difference was found for DSIG during control task (P=0.049), with larger postural sway for those of with-fear-of-falls group. Differences were also found for the intensity of somatomotora sensation in with-fear-of-falls (4 [3-4] points; median and quartiles), compared with no-fear-of-falls (2 [2-3] points; P=0.025). Conclusion: There is significant association between fear-of-falls during MI and the ability to imagine a movement. However, there seems to be no influence of fear-of-falls in the postural adjustements induced by MI. The differences observed in postural sway during control condition suggests a baseline postural “trait” in those with fear-of-falls.