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Attentional requirements of postural control in people with spinal cord injury : the effect of dual task

University of British Columbia

Background: The simultaneous performance of a postural and suprapostural task has been shown to result in the deterioration of the performance of one or both tasks. For people with spinal cord injury (SCI), whose standing balance is challenged, it is unknown the extent to which they rely on attentional resources to maintain quiet stance. The overall aim of this study was to use a dual task paradigm to investigate the attentional requirements for maintaining standing balance in people with SCI. Methods: We recruited 9 adults with incomplete SCI and 8 matched able-bodied controls. Subjects were asked to perform two suprapostural tasks: a mathematical task (counting backwards by 3s) and an auditory reaction time (RT) task with eyes open/closed. Three single task (ST) trials were recorded: i) standing on force plates; ii) math task while seated; iii) RT task while seated. Two dual-task (DT) trials were recorded: i) standing + math task; ii) standing + RT task. The primary outcome measures were the change in performance between ST and DT between SCI and controls for: i) RT, ii) maximum standing time, iii) error ratio and total number of words uttered, and iv) movement reinvestment. Secondary outcomes such as center of pressure (CoP) measures from force plates as well as perceptual measures such as fear, confidence and perceived mental workload were also recorded. Results: SCI subjects stood for shorter duration during DT (stand and count) than ST (stand) compared to controls during eyes closed. Main effects between groups were observed for movement reinvestment, CoP performance, perceived mental effort, fear and confidence. No significant effects were observed for RT task or math task performance. Conclusion: Total standing time during eyes closed is adversely affected with the addition of a math task for SCI subjects. Perceptual measures such as increased fear and perceived mental workload and decreased confidence correspond to increases in postural sway and conscious control of standing in subjects with SCI. Individuals who can stand for >60 seconds eyes closed do not appear to be significantly affected by the addition of a concurrent secondary task of minimal mental workload.  

Text

2015-07-29

Attribution-NonCommercial-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/54225

Kinesiology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/2.5/ca/