Measuring shoulder proprioception: Introducing a new clinical tool - The Shoulder Proprioception Reaching Test (SPReT)

Background: Proprioception, our sense of joint awareness, is a sub-category of somatosensation, known as our “sixth sense”. It is part of our neuromuscular system, responsible for maintaining joint stability and preventing injury, particularly amongst shoulders. Proprioception is affected by injury and a decreased sense of proprioception can cause a predisposition to injury. Despite the importance of proprioception for shoulder stability, there remains no confident way to measure shoulder proprioception in a clinic. Purpose: To present a new clinical tool – The Shoulder Proprioception Reaching Test (SPReT) and to establish the discriminant validity, intra-rater and absolute reliability properties. Study Design: Cross-sectional clinical measurement study. Methods: : A convenience sample of forty healthy participants was used. A single session (120 minutes) involved two bilateral evaluations of reaching movements using the SPReT, with a 30-minute rest period. Twenty participants were randomly selected to further perform a shoulder fatigue protocol of the dominant shoulder, immediately followed by a third SPReT evaluation. The SPReT involves active reaching movements in standing and with eyes closed, towards 7 targets in a star formation (active joint position sense). Discriminant validity (paired t tests), intra-rater reliability (intraclass correlation coefficients [ICC]) and absolute reliability (standard error of measurement [SEM] and minimal detectable change [MDC]) were determined. Results: : The SPReT supports moderate (ICC = 0.45 – 0.71) to good (ICC = 0.77) intra-rater reliability with SEMs ranging from 1.17 to 2.63 cm and MDC 90 from 2.72 to 6.12 cm for all targets. A fatigue effect was found with the superior and the superior-lateral right targets ( P < .05), suggesting possible discriminant validity with the SPReT tool during elevated reaching movements. Conclusions: : The superior target demonstrated the highest discriminant validity, intra-rater and absolute reliability properties and takes less than 5 minutes to evaluate. The evaluation of the superior target only may be suitable for clinical practice upon further methodological investigation for validity, reliability and responsiveness. Future research in encouraged and continues to be ongoing amongst a pathological population. Level of evidence: Level III cross-sectional study.