Figure 1
Diagrammatic illustration of experiment setup (a) and the events measured in the gait cycle (b). The limbs in the crossing cycle are depicted with leading (red lines) and trailing (blue lines) indicators for each occurrence: leading toe-off (T1); leading toe positioned above the obstacle (T2); leading heel strike (T3); trailing toe-off (T4); trailing toe positioned above the obstacle (T5); trailing heel strike (T6).
Figure 2
Diagrammatic illustration of foot placement and clearance parameters for the lead and trail feet during obstacle crossing. (a) Example of horizontal obstacle clearance parameters. (b) Example of vertical obstacle clearance parameters. The dotted lines are used to represent the leading limb, and the solid lines are employed to signify the trailing limb.
Table 1
3 × 3 repeated-measures ANOVA for gait parameters
| Parameters (unit) | Unobstructed | Obstruction 25 | Obstruction 35 | Obstruction effect | Height effect | Obstruction ×Height |
|---|---|---|---|---|---|---|
| Step length (mm) | 714.3 ± 45.5 | 725.6 ± 48.7 | 731.9 ± 58.5 | F (2,74) = 2.68, P = 0.075, η 2 = 0.067 | F (2,37) = 0.19, P = 0.825, η 2 = 0.010 | F (4,74) = 0.31, p = 0.873, η 2 = 0.016 |
| Step width (mm) | 156.2 ± 35.5 | 161.8 ± 44.9 | 163.5 ± 41.9 | F (2,74) = 1.17, p = 0.316, η 2 = 0.031 | F (2,37) = 0.19, p = 0.826, η 2 = 0.010 | F (4,74) = 0.39, p = 0.813, η 2 = 0.021 |
| step velocity (mm/s) | 1.65 ± 0.19 | 1.59 ± 0.19 | 1.55 ± 0.21 | F (2,74) = 25.62, p < 0.001, η 2 = 0.409 | F (2,37) = 7.27, p = 0.002, η 2 = 0.282 | F (4,74) = 1.07, p = 0.377, η 2 = 0.055 |
| TD (mm) | 275.9 ± 44.2 | 315.7 ± 47.9 | 338.7 ± 57.5 | F (2,74) = 37.03, p < 0.001, η 2 = 0.500 | F (2,37) = 0.21, p = 0.814, η 2 = 0.011 | F (4,74) = 0.99, p = 0.418, η 2 = 0.051 |
| HD (mm) | 222.8 ± 28.7 | 194.7 ± 37.4 | 179.7 ± 46.6 | F (2,74) = 14.30, p < 0.001, η 2 = 0.279 | F (2,37) = 0.05, p = 0.949, η 2 = 0.003 | F (4,74) = 0.60, p = 0.662, η 2 = 0.032 |
| TC swing (mm) | 155.1 ± 35.2 | 187.5 ± 46.6 | 201.2 ± 49.3 | F (2,74) = 45.58, p < 0.001, η 2 = 0.552 | F (2,37) = 0.26, p = 0.776, η 2 = 0.014 | F (4,74) = 1.93, p = 0.114, η 2 = 0.094 |
| TC stance (mm) | 144.0 ± 43.2 | 171.3 ± 46.0 | 184.5 ± 53.6 | F (2,74) = 23.58, p < 0.001, η 2 = 0.389 | F (2,37) = 0.27, p = 0.763, η 2 = 0.015 | F (4,74) = 0.58, p = 0.676, η 2 = 0.031 |
| Penultimate (mm) | 967.8 ± 78.0 | 973.7 ± 70.3 | 982.1 ± 82.6 | F (2,74) = 2.06, p = 0.134, η 2 = 0.053 | F (2,37) = 0.21, p = 0.809, η 2 = 0.011 | F (4,74) = 2.35, p = 0.062, η 2 = 0.113 |
Table 2
Comparisons of Step velocity across different height conditions (between-subject effects)
| Parameter | Comparison | Mean ± SD (I) | Mean ± SD (J) | Mean Difference [95% CI] (mm/mm/s) | Cohen’s d | p-Value |
|---|---|---|---|---|---|---|
| Step velocity (mm/s) | 10% vs 20% | 1745.0 ± 176.7 | 1676.4 ± 165.6 | 68.6 [−19.8, 157.0] | 0.41 | 0.126 |
| 10% vs 30% | 1745.0 ± 176.7 | 1513.7 ± 159.1 | 231.3* [114.5, 348.1] | 1.39 | 0.001* | |
| 20% vs 30% | 1676.4 ± 165.6 | 1513.7 ± 159.1 | 162.7* [11.1, 314.3] | 0.99 | 0.034* |
[i] Mean differences (Mean Diff) with 95% confidence intervals (95% CI) were derived from pairwise comparisons. Cohen’s d was calculated as the standardized effect size (|d| ≥ 0.20: small; ≥0.50: medium; ≥0.80: large). Values with asterisks * indicate statistically significant differences (P < 0.05). Values are mean ± standard deviation (Mean ± SD). Negative mean differences indicate lower values in the first condition (I) compared to the second (J).
Figure 3
Each gait parameter under the condition of without carrying boxes, and carrying boxes of 30 × 30 × 25 cm and 30 × 30 × 35 cm that occlude the lower visual field (LVF). Error bars show the mean ± SD, * P < 0.05，** P < 0.01，***P < 0.001.
Figure 4
A priori correlation matrix between key gait parameters under lower-visual-field (LVF) obstruction. Each point represents one obstacle-crossing trial; solid lines denote Pearson regression fits with 95% confidence bands (shaded). Correlation coefficients (r) and Bonferroni-corrected p-values (α = 0.017) are inset. Only correlations surviving correction are reported. *: P < 0.017, **: P < 0.01, ***: P < 0.001. (1) Unobstructed (LVF) (2) Obstruction 25 (3) Obstruction 35. Only correlations surviving Bonferroni correction (α = 0.017) are reported. Values shown in original measurement units (mm/mm/s).