Shoulder irritability differs by standardised measures of movement-evoked pain

ObjectiveIrritability utilises pain behaviour during movement to inform examination and treatment intensity. Standardised measures of movement-evoked pain have not previously been applied to irritability. This study examined whether shoulder pain during standard movements differed by irritability category and level.DesignObservational studySettingResearch laboratoryParticipantsParticipants with shoulder pain (n=40)InterventionIrritability was assessed followed by psychological questionnaires (Fear of Pain Questionnaire, Pain Catastrophizing Scale, Tampa Scale of Kinesiophobia, Center for Epidemiologic Studies-Depression, State-Trait Anger Expression Inventory, Pain Anxiety Symptoms Scale, Pain Self-Efficacy Questionnaire), quantitative sensory testing (pressure pain threshold, heat pain threshold, conditioned pain modulation, temporal summation), and movement-evoked pain (lifting, functional movements, repetitive movements, self-selected task).Main measuresShoulder pain intensity was assessed before, during, and after each task. A t-test and ANOVA examined differences in each movement task by irritability.ResultsPain during the standardised lifting task was significantly higher in individuals categorised as irritable (p=0.03) than not irritable, as well as high irritability compared to moderate (p<0.01). Pain during functional movements was significantly higher in individuals categorised as irritable (p<0.01) compared to not, as well as high compared to low irritability (p<0.01). Performance on repetitive tasks did not significantly differ by irritability category (p=0.63) or level (p=0.44). Change in pain ratings during the self-selected task did not differ by irritability category (p=0.67) or level (p=0.95).ConclusionsPain during standardised, functional movements may differentiate irritability. Clinicians may want to consider functional testing in which pain is assessed during movement for patients with irritable shoulder pain.