Inter- and intrarater clinician agreement on joint motion patterns during gait in children with cerebral palsy

AimThis study aimed to quantify the inter- and intrarater clinician agreement on joint motion patterns in children with spastic cerebral palsy (CP), which were recently specified by a Delphi consensus study. It also examined whether experience with three-dimensional gait analysis (3DGA) is a prerequisite for using the patterns. MethodThe experimental group consisted of 82 patients with CP (57 males, 25 females; uni-/bilateral CP [n=27/55]; Gross Motor Function Classification System levels I to III; mean age 9y 5mo [range 4y-18y]). Thirty-two clinicians were split into experienced' and inexperienced' rater groups. Each rater was asked to classify 3DGA reports of 27 or 28 patients twice. Inter- and intrarater agreement on 49 joint motion patterns was estimated using percentage of agreement and kappa statistics. ResultsTwenty-eight raters completed both classification rounds. Intrarater agreement was substantial' to almost perfect' for all joints (0.64<?<0.91). Interrater agreement reached similar results (0.63<?<0.86), except for the knee patterns during stance (?=0.49, moderate agreement'). Experienced raters performed significantly better on patterns of the knee during stance and ankle during swing. InterpretationApart from some specific knee patterns during stance and ankle patterns during swing, the results suggested that clinicians could use predefined joint motion patterns in CP with good confidence, even in case of limited experience with 3DGA. What this paper adds Intra- and interrater agreement was found on joint motion patterns in cerebral palsy. Intrarater agreement is rater-specific and not generalizable to all clinicians. Experienced raters better identified knee patterns in stance and ankle patterns in swing.