Assessment of Gait Symmetry and Gait Normality Using Inertial Sensors: In-Lab and In-Situ Evaluation - Biomedical Engineering Systems and Technologies - page 224

baseline - follow-up

70

80 60

70

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50

60

40

50

30

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walker crutches one crutch none

30

Fig. 6. Symmetry results according to walking
aid. Box-plot representations of the distribu-
tions. The whiskers represent the smallest and
largest observations, the edges of the box cor-
respond to the lower and upper quartiles, the
horizontal line indicates the median.

20

baseline follow-up

Fig. 5. Symmetry results at baseline and
follow-up. The two distributions are not sta-
tistically significantly different.

baseline - follow-up

100

100

95

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95

90

90

85

walker crutches one crutch none

baseline follow-up

Fig. 8. Normality results according to walking
aid. A Kruskal-Wallis test indicates that the
distribution of no walking aid is significantly
different from distributions of two crutches
and walker.

Fig. 7. Normality results at baseline and at
follow-up. The two distributions are statisti-
cally different according to a Wilcoxon rank
sum test, p < 0.0001.

represented by 1 and no-aid was represented by 4. The resulting Spearman's rank cor-
relation coefficient was r=-0.78, p < 0.0001.
The normality index also correlates well with both average speed, r=-0.79 p < 0.0001,
and normalized average step length, r=-0.76 p < 0.0001. Normality values for each indi-
vidual trial are shown against average speed values in Figure 9, and against normalized
step length in Figure 10. On both plots the linear model approximation is shown as a
solid line, and the 95% confidence interval (CI) for predicted observations is shown
as dotted lines. The mean average speed at baseline, 0.46 ± 0.16 m/s, was significantly

different from the speed at follow-up, 1.06 0.22 m/s, p < 0.0001.

Normality results were also compared to the EQ-5D TM answers that varied the
most between before the surgery and after follow-up, namely mobility (Figure 11),
usual activities (Figure 12), and pain/discomfort (Figure 11). In all cases, there is a

±