Motor excitability in painful musculoskeletal shoulder conditions: A scoping review

ObjectiveAltered motor excitability is a proposed mechanism of musculoskeletal shoulder pain. This scoping review aims to summarise studies examining motor excitability in individuals with painful musculoskeletal shoulder conditions, identify research gaps, and suggest clinical and research insights from these studies.Data SourcesPubMed, EMBASE, CINAHLReview methodsDatabases were searched for studies from January 2004 to April 2026. Studies were included if they assessed motor excitability in participants with painful musculoskeletal shoulder conditions or healthy participants with experimentally induced shoulder pain.ResultsA total of 19 studies were included. Shoulder pain condition, target muscle selection, participant positioning, and measures of motor excitability varied between studies. Moreover, 11 of 16 studies comparing shoulder motor excitability in those with clinical or experimental shoulder pain to controls reported decreases in motor excitability in those with shoulder pain. Two of three studies reporting intervention effects describe increased excitability following interventions in at least one measure.ConclusionShoulder motor excitability appears decreased in those with clinical shoulder pain. Mixed effects of experimental shoulder pain models on motor excitability suggest that more work clarifying the effect of pain on motor excitability changes is warranted. Preliminary studies report increased excitability following interventions, yet the clinical significance of these improvements is unclear. In order to minimise nervous system maladaptations in those with shoulder pain, clinicians may emphasise pain management and consider interventions that enhance motor excitability of the shoulder musculature. Because of heterogeneity in methodology and experimental pain models, further exploration of motor excitability as a mechanism and treatment target in musculoskeletal shoulder pain appears warranted.