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Table 2 Intraclass correlations and limits of agreement

From: Comparison of programs for determining temporal-spatial gait variables from instrumented walkway data: PKmas versus GAITRite

Gait variable

Absolute agreement: ICC(2,1) (95% CI)

Consistency: ICC(3,1) (95% CI)

Mean difference* (SD,% difference)

Limits of agreement 95% CI

Lower

Upper

Speed (cm/s)

1.00 (1.00-1.00)

1.00 (1.00-1.00)

0.34 (0.59, 0.3%)

−0.82

1.50

Cadence (steps/min)

1.00 (1.00-1.00)

1.00 (1.00-1.00)

−0.05 (0.19, 0.0%)

−0.42

0.33

Stride length (cm)

1.00 (1.00-1.00)

1.00 (1.00-1.00)

0.02 (0.38, 0.0%)

−0.73

0.76

Step length (cm)

1.00 (1.00-1.00)

1.00 (1.00-1.00)

0.02 (0.42, 0.0%)

−0.79

0.84

Stride duration (s)

1.00 (1.00-1.00)

1.00 (1.00-1.00)

0.000 (0.001, 0.0%)

−0.002

0.003

Step duration (s)

1.00 (1.00-1.00)

1.00 (1.00-1.00)

0.000 (0.004, −0.1%)

−0.008

0.007

Stance duration (s)

1.00 (1.00-1.00)

1.00 (1.00-1.00)

0.005 (0.009, 0.7%)

−0.012

0.022

Swing duration (s)

0.99 (0.99-1.00)

1.00 (0.99-1.00)

−0.003 (0.005, −0.7%)

−0.013

0.007

Double support duration (s)

1.00 (0.99-1.00)

1.00 (1.00-1.00)

0.005 (0.010, 1.5%)

−0.014

0.025

Stance time as a percentage of cycle time (%)

1.00 (0.99-1.00)

1.00 (0.99-1.00)

0.22 (0.39, 0.3%)

−0.56

1.00

Double support time as a percentage of cycle time (%)

0.99 (0.99-1.00)

1.00 (0.99-1.00)

0.43 (0.89, 1.4%)

−1.31

2.17

Base width (cm)

0.86 (−0.03-0.96)

0.97 (0.95-0.98)

−1.62 (0.82, −17.4%)

−3.22

−0.02

Foot angle (°)

0.97 (0.89-0.99)

0.98 (0.97-0.98)

0.69 (0.95, 9.7%)

−1.18

2.56

Variability (SD) in Stride Length (cm)

0.95 (0.93-0.97)

0.96 (0.94-0.97)

0.01 (0.48. 3.6%)

−0.84

1.06

Variability (SD) in Step Length (cm)

0.84 (0.78-0.89)

0.84 (0.78-0.89)

−0.01 (0.56, −0.5%)

−1.10

1.08

Variability (SD) in Stride Duration (s)

1.00 (0.99-1.00)

1.00 (0.99-1.00)

0.001 (0.003, 1.6%)

−0.006

0.007

Variability (SD) in Step Duration (s)

0.98 (0.97-0.98)

0.98 (0.97-0.98)

−0.001 (0.005, −2.7%)

−0.009

0.008

Variability (SD) in Step Width (cm)

0.97 (0.95-0.98)

0.98 (0.97-0.98)

0.08 (0.20, 3.9%)

−0.32

0.47

  1. ICC = Intraclass Correlation, CI = confidence interval, SD = standard deviation.
  2. *Negative differences indicate GAITRite® higher than PKmas®.
  3. ICC (2,1) absolute agreement, ICC(3,1) consistency (with 95% CI), mean difference (with SD and mean difference as a percentage of the mean GAITRite® value), and 95% limits of agreement for the total cohort. All ICCs were significant at p < 0.001.