Intra- and Inter-Rater Reliability of a Ballet-based Dance Technique Screening Instrument

To investigate intra- and inter-rater reliability of a ballet-based Dance Technique Screening Instrument used by physical therapists (PTs) and student PTs (SPTs) with prior dance medicine or dance experience.

Ten pre-professional dancers were video-recorded in the sagittal and frontal planes while performing four dance sequences: 1) second position grand plié; 2) développé à la seconde; 3) single-limb passé relevé balance; and 4) jumps in first position. Dance videos and electronic versions of the demographics and scoring forms were provided through a secure online survey to 28 PTs and SPTs who served as raters. Raters reviewed a training video prior to scoring the 10 dancers. Raters were asked to repeat their assessments 1-2 wks later. Intraclass correlations (ICC) were assessed for all-raters, PTs, and SPTs for total and sequence scores.

Twenty-eight raters assessed the videos one time. Inter-rater reliability was ICC=0.98 (CI95=0.96-0.99) (all-raters), with PTs and SPTs displaying similar values (ICC=0.96 and 0.96, respectively). Eighteen raters (11 PTs, 7 SPTs) repeated the video analysis. Intra-rater reliability was ICC=0.78 (CI95=0.72-0.83) with PTs ICC=0.81 and SPTs ICC=0.70.

Correlations were high for all-raters. SPTs were as reliable as PTs in inter-rater comparisons. PTs exhibited higher intra-rater reliability compared to SPTs. These results substantiate the reliability of a standardized testing instrument to conduct dance technique assessment. Validity of this instrument was demonstrated in a previous study which found dancers with better technique were less likely to sustain injury. The ability to identify technique deficits can guide preventative programs that may reduce injury risk.

Level III.