Table 3.
Dual Task Effects for All Gait Parameters and Cognitive Outcomesa.
| Domain | Variable | Single task | Dual task | Z value | P value | Dual task effect (%) |
|---|---|---|---|---|---|---|
| Pace | Gait speed (m/s), mean (SD) | 1.19 (0.19) | 1.13 (0.27) | −3.26 | .001 | −4.94 (11.91) |
| Step length (m), mean (SD) | 0.65 (0.09) | 0.62 (0.09) | −4.84 | <.001 | −3.77 (7.09) | |
| Swing time variability (ms) | 14.28 (6.66) | 16.04 (8.90) | −4.57 | <.001 | −10.72 (32.47) | |
| Rhythm | Step time (ms) | 544.50 (43.00) | 548.00 (58.50) | −1.31 | .189 | 0.38 (7.2) |
| Swing time (ms) | 392.50 (35.50) | 385.50 (43.00) | −2.10 | .037 | 1.27 (4.27) | |
| Stance time (ms) | 694.50 (71.75) | 705.50 (98.25) | −2.53 | .011 | −0.75 (9.61) | |
| Variability | Step speed variability (m/s) | 0.04 (0.02) | 0.05 (0.02) | −3.47 | .001 | −11.49 (40.20) |
| Step length variability (m) | 0.02 (0.01) | 0.02 (0.01) | −3.84 | <.001 | −10.49 (42.12) | |
| Step time variability (ms) | 14.38 (7.18) | 16.53 (10.62) | −4.24 | <.001 | −13.81 (42.38) | |
| Stance time variability (ms) | 16.49 (6.90) | 20.24 (13.19) | −4.91 | <.001 | −23.42 (56.17) | |
| Asymmetry | Swing time asymmetry (ms) | 9.00 (11.50) | 10.00 (10.00) | −0.65 | .518 | −7.74 (130.24) |
| Step time asymmetry (ms) | 12.00 (14.50) | 13.00 (16.00) | −0.83 | .404 | 0.00 (116.12) | |
| Stance time asymmetry (ms) | 9.00 (10.50) | 10.00 (12.50) | −0.264 | .792 | 0.00 (130.36) | |
| Postural control | Step length asymmetry (m) | 0.02 (0.03) | 0.02 (0.02) | −1.45 | .147 | −4.24 (109.39) |
| Step width (m) | 0.08 (0.03) | 0.09 (0.03) | −4.50 | <.001 | −4.41 (11.76) | |
| Step width variability (m) | 0.02 (0.01) | 0.02 (0.01) | −2.16 | .031 | 4.59 (28.15) | |
| Cognition | Reaction time (RT) (s) | 0.99 (0.26) | 1.10 (0.13) | −5.39 | <.001 | −11.37 (24.68) |
| Standard deviation of RT | 0.30 (0.27) | 0.37 (0.09) | −2.02 | .043 | −39.19 (126.29) | |
| Accuracy (%) | 100.00 (6.67) | 96.55 (8.70) | −1.36 | .174 | 0.00 (4.19) |
a
Gait speed and step length (single task, dual task, and dual task effect) presented as mean (SD). All other presented as median (interquartile range). Dual task effect is presented in negative or positive values where negative values indicates a dual-task cost, and positive values a dual-task benefit.