Is rotator cuff related shoulder pain a multidimensional disorder? An exploratory study

Background and aims Rotator cuff related shoulder pain has been associated with factors from multiple dimensions such as strength changes, psychosocial measures, comorbidities and level of education. However, to date little research has been undertaken to evaluate which factors explain the greatest variance in pain and disability levels in people with rotator cuff related shoulder pain. The objective of this study was therefore to evaluate which multidimensional examination findings were associated with higher pain and disability in a primary care cohort with rotator cuff related shoulder pain. Methods This was an exploratory cross-sectional cohort study. Sixty-seven participants with rotator cuff related shoulder pain were assessed for: pain intensity, disability; demographic, psychological, social and lifestyle characteristics, and isometric strength of shoulder internal and external rotator muscles. Univariable associations between pain intensity/disability and each variable were assessed using linear regression. Variables with univariable associations (p < 0.1) were entered into backwards stepwise multivariable regression models. Results The multivariable model for pain intensity included sleep and perceived persistence and explained 46.5% of the variance (37.6% uniquely by sleep, 5.4% uniquely by perceived persistence). The multivariable model for disability included sleep and sex and explained 26.8% of the variance (4.5% shared by predictors, 16.4% uniquely by sleep, 5.9% uniquely by sex). Conclusions Rotator cuff-related shoulder pain and disability are associated with sleep disturbance, perceived symptom persistence and sex. Rotator cuff related shoulder pain may be considered a multidimensional disorder. Implications Clinicians need to evaluate sleep and perceived symptom persistence in people with rotator cuff related shoulder pain. Future research may examine whether management strategies for RCRSP directed towards these factors afford improved treatment outcomes.