Reliability of a sense of position test and normative values for young swimmers

Abstract

BackgroundProprioception, particularly joint position sense (JPS), is essential for motor control and may be impaired in athletes with shoulder pain or dysfunction. Given swimmers’ frequent exposure to high shoulder amplitudes, accurate assessment of shoulder JPS is relevant for monitoring function and detecting early impairments.AimsTo investigate the intra- and inter-rater reliability of a laser pointer-assisted shoulder JPS test in competitive swimmers and to explore potential associations between JPS performance and intrinsic/extrinsic factors.MethodsThis observational study included 48 healthy swimmers aged 12–20 years. Participants performed a shoulder flexion angle reproduction test using a laser pointer, targeting 55°, 90°, and 125°. Measurements were recorded in degrees and centimeters. Intra- and inter-rater reliability were assessed using the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC). Agreement was further evaluated using Bland–Altman analysis. Multivariate regression was applied to examine the influence of age, sex, pain, training characteristics, and swim style on JPS.ResultsInter-rater reliability ranged from moderate to excellent, while intra-rater reliability ranged from poor to moderate, with greater variation observed at 125°. Errors were smallest at 90°, while the 55° angle produced the most variation. Despite high MDC values, agreement was acceptable across conditions. Shoulder pain in the past year significantly affected JPS at 125°, while other factors had no consistent influence.ConclusionsThe shoulder JPS test using a laser pointer showed acceptable reliability and can be feasibly applied in sports and clinical settings, especially to monitor proprioceptive function in swimmers. The test at 90° had the best agreement, but lower and higher amplitudes like 55° and 125° of shoulder flexion may detect dysfunctions. However, pain history may chronically affect JPS at high amplitudes.