Changes in Pain-Related Fear Predict Shoulder Disability in Rotator Cuff Tendinopathy With Resistance Exercise

OBJECTIVE: To determine the trajectory of (i) change in pain-related fear and catastrophizing factors, (ii) changes in pain-related fear and catastrophizing by treatment satisfaction groups, and (iii) the relationship between pain-related fear trajectories, and catastrophizing factors and shoulder disability during an 8-week resistance exercise program. DESIGN: Prospective longitudinal observational study METHODS: Sixty-four people with rotator cuff tendinopathy completed the exercise protocol. Outcomes of Penn Shoulder Score (Penn) and Optimal Screening for Prediction of Referral and Outcome-Yellow Flag (OSPRO-YF) were assessed at baseline, 2, 4, and 8 weeks. Patient Acceptable Symptom State (PASS) defined satisfaction with treatment at 8 weeks. RESULTS: All pain-related fear and catastrophizing measures changed over time during resistance exercise (p<0.01) but differed by PASS-defined responder and non-responder groups. For FABQ-W, non-responders had an increase (0.63pt) while responders had a decrease (-3.5pt) [mean difference=4.2pt (95%CI: −7.6, −0.7); p = 0.02]. For TSK-11, non-responders had less of a decrease (-0.1) than responders (-3.2pt) [mean difference=3.1pt (95%CI: −5.9, −0.3); p = 0.03]. Reduced shoulder disability was related to less pain-related fear and catastrophizing (p<0.01), and differed by responder group. Non-responders had no relationship between change in pain-related fear and catastrophizing and disability (p>0.05); responders had an overall negative relationship (p<0.04). CONCLUSION: Pain-related fear and catastrophizing changed over time for individuals with rotator cuff tendinopathy, and changes varied by participant. Those who were not satisfied at 8 weeks had higher levels of pain-related fear and catastrophizing, while those who were satisfied had reduced pain-related fear and catastrophizing. Less pain-related fear and catastrophizing was related to decreased disability.