Intra-rater reliability of goniometry to measure scapular protraction and retraction

•Scapular mobility is uniquely challenging to assess and currently there is no reliable goniometric technique described in the literature to measure scapular protraction and retraction.•The current study examined intra and inter-rater reliability of a goniometric technique using the superior angle and acromion as landmarks to measure the position of the scapula relative to the frontal plane.•SEM for repeat measures by the expert and novice raters was < 4.5° and < 3.9°respectively, and SEM between evaluators was < 5.0°, demonstrating absolute reliability similar to that of other goniometric assessments.•Minimum detectable change (MDC) values as a percentage of the mean (% MDC), reflecting the degree of measurement error as a percentage of the available motion, ranged between 15.9-43.7% for intra-rater reliability and 21.9-52.8% for inter-rater reliability. Observational, descriptive design. Despite scapular mobility being essential for the completion of activities of daily living (ADLs), there is currently no established, a reliable goniometric technique to measure scapular protraction and retraction. A proposed method has shown clinically significant inter-rater reliability for a goniometric technique for these measurements. This observational descriptive study examined the intra-rater reliability of a goniometric technique to assess scapular protraction and retraction among a sample of healthy adults. An occupational therapist who is a certified hand therapist (CHT) and an occupational therapy student used goniometry to measure the neutral (resting), protracted, and retracted positions of the right and left scapula for a sample of healthy young adults (n = 54; a total of 108 data points for each measurement). These measurements were compared to analyze intra-rater and inter-rater reliability. For measurements of the scapula in neutral, protraction, and retraction, the standard error of measure (SEM) for repeat measures by the expert and novice raters was < 4.5° and < 3.9° respectively and ICC values ranged from poor to moderate (0.37-0.63). The SEM for measures between evaluators was < 5.0° and the ICC was poor (0.16-0.35). Minimum detectable change (MDC) values as a percentage of the mean (% MDC) ranged between 15.9 and 43.7% for intra-rater reliability and 21.9-52.8% for inter-rater reliability. The results of the study were mixed; variance of less than 5° for repeat measures by the same rater and measures between raters suggest clinically acceptable re