Shoulder dysfunctions are among the leading causes of musculoskeletal pain, often associated with a reduced range of motion and subsequent functional impairments. Emerging evidence suggests that psychological issues, such as kinesiophobia, pain catastrophizing, and increased central sensitivity, might play a role in pain perception and shoulder functional performance. Additionally, the reduced range of motion has been significantly associated with pain severity and physical disability in these patients. However, the relationship between psychological issues and shoulder range of motion remains unclear.

This secondary analysis aimed to investigate whether the reduced shoulder range of motion is associated with negative psychological factors in individuals with musculoskeletal shoulder pain.

A total of 159 individuals (68 females, 39 ? 12.5 years old) with musculoskeletal shoulder pain (44.5 ? 55.9 months of pain) were assessed. Sociodemographic data and pain intensity (Numerical Pain Rating Scale, NPRS, 0–10) were recorded based on self-report. Shoulder range of motion for external rotation and abduction (degrees) were measured using inclinometry (Acumar, Model ACU 360, Lafayette Instrument Company). Kinesiophobia (Tampa Scale for Kinesiophobia, TSK), pain catastrophizing (Pain Catastrophizing Scale, PCS), and central sensitivity (Central Sensitization Inventory, CSI) were the psychological factors assessed using specific Patient Reported Outcome Measures. Two multiple linear regression analyses were performed to investigate the association between each shoulder range of motion (dependent variables) and psychological factors (independent variables). The models were adjusted using the ordinary least squares regression method, with statistical significance threshold set at p < 0.05. The assumptions of linear regression were verified, including normality of residuals, homoscedasticity, and absence of multicollinearity.

For external rotation range of motion, the model indicated that psychological factors explained 5.1% of the variation in range of motion (R = 0.226; R² = 0.051, p = 0.043). Central sensitivity’s (ß = -0.19; p = 0.02) contribution was significant for the model, while kinesiophobia (ß= -0.09; p = 0.25), and catastrophizing (ß= 0.02; p = 0.77) were not able to explain external range of motion. Conversely, for abduction range of motion, psychological predictors accounted for only 0.9% of the variation (R = 0.096, R² = 0.009, p = 0.699), with no contribution of any of the psychological predictors.

Kinesiophobia, pain catastrophizing, and central sensitivity might explain the decrease in range of motion of shoulder external rotation; however, they did not affect shoulder abduction. However, individuals with higher signs of central sensitivity are more likely to present lower external rotation range of motion. Therefore, other factors may be involved in shoulder range of motion limitations and might be better investigated.

These findings underscore the role of psychological factors in restricting shoulder external rotation, highlighting the need for therapeutic approaches that integrate both psychological and biomechanical aspects in the management of musculoskeletal shoulder pain.