Measuring Upper Limb Active Joint Position Sense: Introducing a New Clinical Tool - the Upper Limb Proprioception Reaching Test

Background: Proprioception is our sense of body awareness, including the sub-category of active joint position sense (AJPS). AJPS is fundamental to joint stability and movement coordination. Despite its importance, there remain few confident ways to measure upper limb AJPS in a clinic.Objective: To assess a new AJPS clinical tool, the Upper Limb Proprioception Reaching Test (PRO-Reach; seven targets), for discriminant validity, intra-rater and absolute reliability.Design: Cross-sectional measurement study.Methods: Seventy-five healthy participants took part in a single session with 2 consecutive evaluations (E1 and E2) (within-day reliability). Twenty participants were randomly selected to perform a dominant shoulder fatigue protocol (discriminant validity), whereafter a third evaluation was repeated (E3). The PRO-Reach was analyzed with paired t tests (discriminant validity), intra-class correlation coefficients (ICCs) and minimal detectable change [MDC]) (intra-rater: within-day and between-trial relative and absolute reliability).Results: The PRO-Reach supports moderate (mostly superior targets) to excellent (mostly inferior targets) reli-ability. Between-trial ICCs (T1/T2/T3) varied between 0.72 and 0.90, and within-day (E1/E2) ICCs between 0.45 and 0.72, with associated MDC95 values (3.9-5.0 cm). The overall scores (seven targets) supported the strongest within-day reliability (ICC = 0.77). The inferior targets demonstrated the highest between-trial and within-day reliability (ICCs = 0.90 and 0.72). A fatigue effect was found with the superior and superior-lateral targets (P < .05).Conclusions: The inferior targets and overall scores demonstrate the strongest reliability. The use of the PRO-Reach tool may be suitable for clinical use upon further psychometric testing amongst pathological populations.Level of evidence: Level III cross-sectional study.