Agreement between physiotherapists on quality of movement rated via videotape

Background: Although achieving quality of movement after stroke is an important aim of physiotherapy it is rarely measured objectively or described explicitly.
Objective: To test whether physiotherapists agree on a composite measure of quality of movement.
Setting: A movement analysis laboratory Subjects: Ten stroke patients and 10 healthy age-matched volunteers.
Design: Prospective correlational.
Procedure: All subjects were videofilmed performing three trials of six standardized functional tasks. Two videotapes were made, each with a different randomized order of appearance of the trials. Ten senior physiotherapists independently rated the videotapes twice using a 100-mm visual analogue scale.
Analysis: Analysis of variance models were fitted to transformed data. Estimates of components of variance were calculated and presented as a percentage of the total variance for differences, within subjects (intra-subject), between raters (inter-rater) and within raters (intra-rater). An acceptable percentage was set at less than 10%.
Results: The percentage of intra-subject variance ranged from 1% (pick up box and walking) to 9% (step on block). The percentage of inter-rater variance ranged from 18% (pick up pencil) to 38% (sit to stand). The percentage of intra-rater variance was less than 1% for all tasks.
Conclusions: Although physiotherapists disagreed with each other on quality of movement they were more consistent in their own scoring.