Thermographic assessment of shoulder muscles in rotator cuff injuries: Associations with pain, sleep quality, function and quality of life

OBJECTIVE: This exploratory study investigated associations between infrared thermography-derived skin temperatures in shoulder muscles and pain sensitivity, sleep quality, function, and quality of life in individuals with unilateral rotator cuff injuries. METHODS: In this cross-sectional study, 85 participants (53 females, 32 males) with rotator cuff injuries underwent thermographic imaging of the trapezius, deltoid, biceps, brachioradialis, supraspinatus, and subscapularis muscles. Outcomes included Pressure Pain Threshold (PPT), Visual Analogue Scale (VAS) pain scores, Pittsburgh Sleep Quality Index (PSQI) scores, Disabilities of the Arm, Shoulder, and Hand (DASH) scores, and Short Form-36 (SF-36) subdomains. Correlations were analysed using Pearson or Spearman tests. RESULTS: Skin temperatures of the trapezius and deltoid muscles showed positive correlations with PPT (rho = 0.235-0.422, p < 0.05) and negative correlations with DASH scores (rho = -0.228 to -0.233, p < 0.05). Temperatures of the deltoid, biceps, brachioradialis, and subscapularis correlated negatively with activity-related pain (rho = -0.234 to -0.301, p < 0.05). Biceps and brachioradialis temperatures were negatively correlated with PSQI scores (rho = -0.215 to -0.269, p < 0.05). Subscapularis temperature correlated positively with SF-36 subdomains, including Physical Role (rho = 0.308, p = 0.004) and General Health (rho = 0.276, p = 0.011). No significant correlations were observed for supraspinatus temperature or pain at rest/night. CONCLUSION: This analysis suggests that infrared thermography reveals muscle-specific thermal patterns associated with clinical outcomes in rotator cuff injuries, supporting its potential as a non-invasive diagnostic tool for personalised assessment and management. These preliminary findings warrant confirmation in future hypothesis-driven studies.