Psychological predictors of pain expression and activity intolerance in chronic pain patients.

Recent research suggests that communicative and protective pain behaviors represent functionally distinct subsystems of behavior associated with pain. The present research examined whether components of pain experience such as pain severity, catastrophizing and fear of pain were differentially associated with communicative and protective pain behaviors. It was predicted that pain severity would be associated with decreased physical tolerance and heightened expression of pain behavior. It was also predicted that pain catastrophizing would be preferentially associated with communicative pain behaviors, and fear of pain would be preferentially associated with protective pain behaviors and decreased physical tolerance. To test these predictions, work-disabled patients with musculoskeletal pain conditions (N=72) were filmed as they participated in a simulated occupational lifting task. Multiple regressions revealed that pain severity was uniquely associated with decreased physical tolerance and increased expression of protective pain behaviors. Pain catastrophizing was uniquely associated with the expression of both communicative and protective pain behaviors. Fear of pain was associated with physical tolerance and protective pain behaviors but not when controlling for pain severity. This study provides additional evidence for the functional distinctiveness of different types of pain expression and provides preliminary evidence for the functional distinctiveness of pain expression and activity intolerance. Discussion addresses the processes by which psychological factors might influence the display of different types of pain behaviors. Discussion also addresses how different types of interventions might be required to specifically target the sensory and behavioral dimensions of the pain system.