THE EFFECT OF TIME OF DAY, THE TEST-RETEST RELIABILITY AND THE RELATIONSHIP OF GAIT OUTCOME MEASURES WITH FATIGUE IN PERSONS WITH MULTIPLE SCLEROSIS
One of the biggest challenges persons with multiple sclerosis (pwMS) are facing is difficulty in walking and this is related to decrease in quality of life (QOL). The throughout day variability of walking capacity and everyday unpredictability of symptoms, along with perceptions of fatigue may be related to the reduced walking ability and participation in functional activity. Aims and Hypotheses: The aims were to analyse the effect of time of day on walking and determine the between-day retest reliability of the tested 3D gait kinematics analysis and the 10-meter (10mWT) walking performance test. This study also aimed to determine the correlation between perceived fatigue severity (Fatigue Severity Score, FSS) and the walking performance outcome measures; 10mWT and 6MWT. We hypothesized that there is no effect of time of day on walking. A high test-retest reliability (ICC > 0.7) is hypothesized for gait kinematics and the 10mWT. And, the third hypothesis is that there is no significant correlation between perceived fatigue and walking performances. Methodology: In this secondary data study, within day differences of gait tested between morning (AM) and afternoon (PM) were analysed using paired t-test and Wilcoxon Signed Rank test; while test-retest reliability of the outcome measures assessed for between-day repeatability was evaluated using Intraclass Correlation Coefficient (ICC). The correlation between fatigue score and the walking measures were tested with Pearson Correlation Coefficient. Results: There is no difference in gait kinematics and walking performance assessed in AM and PM sessions. We found moderate to good reliability of gait kinematics and 10mWT as indicated by the ICC. Lastly, there is no statistically significant correlation between self-reported fatigue and measures of walking capacity. Conclusion: Based on the results, this study suggests that pwMS do not necessarily walk differently in the afternoons compared to mornings. The retest reliability offered fulfilment in knowledge gap regarding between-day reliability testing. Self-reports of fatigue are less likely to associate with objective walking ability suggesting that there may be other influences to walking performance in pwMS, and this requires further research.