Development and external validation of a musculoskeletal ultrasound-based prediction model for limited shoulder range of motion in nursing staff with neck-shoulder pain: a cross-sectional study.

Background: Nurses with neck-shoulder pain are at high risk of developing limited shoulder range of motion (ROM), but early prediction tools are lacking. This study aimed to identify risk factors using clinical data and musculoskeletal ultrasound (MSKUS), and to develop and validate a prediction model. Methods: A total of 210 nurses with neck-shoulder pain (100 with limited ROM, 110 with normal ROM) from a tertiary hospital were enrolled. Univariate and multivariate logistic regression analyses were performed to establish a prediction model, which was externally validated in 63 additional nurses. Results: Multivariate analysis identified age, average sleep duration on workdays (ASDW), daily overhead arm duration (DOAD), glenohumeral joint effusion (GLE), subacromial-subdeltoid bursa effusion (SASDBE), and long head of biceps tendon sheath effusion (LHBTE) as independent risk factors. The prediction model demonstrated excellent discrimination with an area under the ROC curve (AUC) of 0.956, sensitivity of 0.910, and specificity of 0.864. External validation yielded an AUC of 0.938, sensitivity of 0.833, and specificity of 0.821. Conclusion: The model incorporating age, ASDW, DOAD, GLE, SASDBE, and LHBTE shows excellent predictive performance for limited shoulder ROM in nursing staff with neck-shoulder pain.