Test-retest reliability of spatial and temporal gait parameters in children with cerebral palsy as measured by an electronic walkway.

PURPOSE: The purpose of this study was to examine test-retest reliability of seven selected temporal and spatial gait parameters and asymmetry measures in children with cerebral palsy.

METHOD: Seventeen children with CP between 3 and 13 years of age walked at three different speeds across an electronic walkway of 5.2m. The tests were repeated after approximately 25 min. The scores were normalized to a walking speed of 1.1m/s to avoid the confounding effect of gait speed on speed dependent gait parameters. Intraclass correlation coefficients (ICC(1,1) and ICC(3,1)) with 95% confidence intervals, within-subject standard deviation (S(w)) and smallest detectable difference (SDD) were calculated.

RESULTS: The relative reliability of cadence, step length, stride length and single stance time was high to excellent (ICC(1,1) between 0.73 and 0.95), while it was poor for step width (ICC(1,1)=0.27 and 0.35). The relative reliability for two calculated asymmetry measures were high for the step length index (ICC(1,1)=0.82) and moderate for the single stance time index (ICC(1,1)=0.49). The absolute reliability values for all gait parameters are reported.

CONCLUSIONS: Five of seven gait parameters measured by an electronic walkway and normalized to a common walking speed, appear to be highly repeatable in a short-term time span in children with CP who were able to walk without assistive walking devices, provided sufficient cognitive function.