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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.