The role of pain catastrophizing and pain acceptance in performance-based and self-reported physical functioning in individuals with fibromyalgia and obesity

Impaired physical functioning is one of the most critical consequences associated with fi-bromyalgia, especially when there is comorbid obesity. Psychological factors are known to contribute to perceived (i.e., subjective) physical functioning. However, physical function is a multidimensional concept encompassing both subjective and objective functioning. The contribution of psychological factors to performance-based (i.e., objective) functioning is unclear. This study aims to investigate the contribution of pain catastrophizing and pain acceptance to both self-reported and performance-based physical functioning. In this cross-sectional study, 160 participants completed self-report measures of pain catastrophizing, pain acceptance, and pain severity. A self-report measure and a performance-based test were used to assess physical functioning. Higher pain catastrophizing and lower pain acceptance were associated with poorer physical functioning at both self-reported and performance-based levels. Our results are consistent with previous evidence on the association between pain catastrophizing and pain acceptance with self-reported physical functioning. This study contributes to the current literature by providing novel insights into the role of psychological factors in performance-based physical functioning. Multidisciplinary interventions that address pain catas-trophizing and pain acceptance are recommended and might be effective to improve both perceived and performance-based functioning in women with FM and obesity.