Movement-Evoked Pain and Temporal Summation in Individuals with Symptomatic Rotator Cuff Tears: A Cross-Sectional...

Musculoskeletal shoulder pain due to rotator cuff (RC) tears is a prevalent condition that significantly impacts function and quality of life. Understanding the underlying pain mechanisms, including movement-evoked pain (MEP) and pain facilitation phenomena such as temporal summation (TS), is essential for improving targeted interventions. This cross-sectional study examined relationships among TS, pain at rest, and MEP in 85 individuals with symptomatic RC tears. Mechanical TS was assessed on the contralateral forearm using standardized mechanical stimuli, while pain at rest and MEP during active arm elevation were measured via numerical rating scales. Spearman's correlations were performed for the overall cohort and stratified by pain duration (<3 months, acute; ≥3 months, chronic). Weak but statistically significant correlations were found between TS and MEP (r = 0.23, p = 0.02) and between pain at rest and MEP (r = 0.30, p = 0.005), whereas no correlation existed between TS and pain at rest. The logistic regression model showed limited predictive ability. These exploratory findings suggest partially overlapping but distinct pain mechanisms in RC tear patients and should be interpreted as hypothesis-generating, warranting validation in larger, prospective cohorts.