Video analysis software increases the interrater reliability of video gait assessments in children with cerebral palsy

The aim of this study was to determine the effect of using video analysis software on the interrater reliability of visual assessments of gait videos in children with cerebral palsy. Two clinicians viewed the same random selection of 20 sagittal and frontal video recordings of 12 children with cerebral palsy routinely acquired during outpatient rehabilitation clinics. Both observers rated these videos in a random sequence for each lower limb using the Observational Gait Scale, once with standard video software and another with video analysis software (Dartfish (R)) which can perform angle and timing measurements. The video analysis software improved interrater agreement, measured by weighted Cohen's kappas, for the total score (kappa 0.778 -> 0.809) and all of the items that required angle and/or timing measurements (knee position mid-stance kappa 0.344 -> 0.591; hindfoot position mid-stance kappa 0.160 -> 0.346; foot contact mid-stance kappa 0.700 -> 0.854; timing of heel rise kappa 0.769 -> 0.835). The use of video analysis software is an efficient approach to improve the reliability of visual video assessments. (C) 2011 Elsevier B.V. All rights reserved.