Test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain in patients with rotator cuff-related shoulder pain

Abstract

Background: The number of researchers and clinicians using movement-evoked pain and sensitivity to movement-evoked pain to assess shoulder pain has increased. However, the intrarater test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain in people with rotator cuff-related shoulder pain (RCRSP) is still unknown. Objective: We examined the intrarater test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain in participants with RCRSP. Methods: Seventy-four participants with RCRSP performed five trials of active shoulder abduction to elicit pain under two experimental conditions: active shoulder abduction to the onset of pain and maximum range of motion (ROM). The primary outcome measures were pain intensity and ROM. Test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain was examined using intraclass correlation coefficient (ICC3,1) and minimal detectable change (MDC90). Results: The reliability of movement-evoked pain under both experimental conditions was good to excellent (ICC: 0.81 to 0.95), while the reliability of sensitivity to movement-evoked pain was poor in both conditions (ICC≤0.45). The MDC90 for pain intensity was 1.6 and 1.8 during shoulder abduction to the onset of pain and maximum ROM, respectively. The MDC90 for ROM was 17.5° and 11.2° during shoulder abduction to the onset of pain and maximum ROM condition, respectively. Conclusion: This study confirms movement-evoked pain testing during active shoulder abduction to the onset of pain or maximum ROM condition is reliable to assess pain associated with movement in patients with RCRSP. The minimal detectable change score of movement-evoked pain can guide clinicians and researchers on how to interpret changes in these outcomes.