Table 1.
Tasks
| Tasks | ||||||
|---|---|---|---|---|---|---|
| 1) 10MWT | 2) 10MWT context | 3) IWW obstacles | ||||
| 1a) 10MWT |
1b) 10MWT + cognitive task |
2a) 10MWT context |
2b) 10MWT context + cognitive task |
3a) IWW obstacles |
3b) IWW obstacles + cognitive task |
|
| Outcome measures | ||||||
| Walking speed | Walking speed (m/s), primary outcome measure | Walking speed (m/s) | (Context-specific) walking speed (m/s) | (Context-specific) walking speed (m/s) | (Context-specific) walking speed (m/s) | (Context-specific) walking speed (m/s) |
| Walking adaptability |
Walking-adaptability score (0–10) Sum of subscores for obstacle avoidance, tandem walking, and targeted steppinga |
Walking-adaptability score (0–10) Sum of subscores for obstacle avoidance, tandem walking, and targeted stepping a |
Walking-adaptability score (0–10) Sum of the points received for the first 10 obstacles b |
Walking-adaptability score (0–10) Sum of the points received for the first 10 obstacles b |
||
| Cognitive performance | Cognitive performance (the number of correct subtractions per second; n/s) | Cognitive performance (the number of correct subtractions per second; n/s) | Cognitive performance (the number of correct subtractions per second; n/s) | |||
| Cognitive-motor interference |
Cognitive-motor interference (%) Average of the dual-task effects of walking speed and the cognitive-task performance score (with sitting as single-task reference) |
Cognitive-motor interference (%) Average of the dual-task effects of walking speed, the walking-adaptability score, and the cognitive-task performance score (with sitting as single-task reference) |
Cognitive-motor interference (%) Average of the dual-task effects of walking speed, the walking-adaptability score, and the cognitive-task performance score (with sitting as single-task reference) |
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aTo be classified as a successfully avoided obstacle, both feet had to stay clear of the obstacle without stepping next to it, circumduction of the hip, or hitting the obstacle (one point per successfully avoided obstacle, with a maximum of three points). For successful targeted stepping, the whole foot had to be placed within the target without allowing intermediate steps (one point per successfully hit target, with a maximum of three points). Because the total number of steps for tandem walking was expected to vary among participants (5.41 ± 1.77 steps, according to the results), we categorized successful tandem walking based on the percentage of correct steps within the narrow-walking path: one point for 0–25% correct steps, two points for 26–50% correct steps, three points for 51–75% correct steps, and four points for 76–100% correct steps
bTo be classified as a successfully avoided obstacle, both feet had to be placed outside the area of the projected obstacle (i.e., no overlap of shoe and obstacle; one point per obstacle)