Association between pain intensity, range of motion, disability, and mental health-related quality of life variables in frozen shoulder: A cross-sectional study.

INTRODUCTION: No studies have highlighted the impact of mental health-related quality of life, disability, range of motion (ROM), and pain in patients with frozen shoulder. The aim of this study was to analyze the association between such variables during the first physiotherapy consultation.

METHODS: This cross-sectional study followed the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Participants were recruited between January and October 2024. Each participant anonymously filled out the Shoulder Pain and Disability Index-pain subscore (dependent variable). The Disabilities of the Arm, Shoulder, and Hand questionnaire, the 36-Item Short Form Health Survey, measurement for flexion (FL), abduction, and external rotation ROM (independent variables) were further collected. Statistical analysis was performed using multivariable linear regression-modeling all independent variables simultaneously and adjusting for confounding factors.

RESULTS: Were included 149 subjects (53% female). Significant association was found between pain and disability (standardized coefficient = 13.65, 95%CI 10.38 to 16.92, p < 0.01), and between pain and FL (standardized coefficient = -3.95 95%CI -7.43 to -0.47, p = 0.03).

DISCUSSION: Pain resulted as primary determinant of disability. A significant association between pain and FL was also observed, with FL being the most sensitive movement to pain. While pain limits physical function, its psychological impact, assessed through such outcome measures used, may not yet be evident.