Pain Catastrophizing Mediates the Effect of Psychological Inflexibility on Pain Intensity and Upper Extremity Physical Function in Patients with Upper Extremity Illness.

Abstract

Psychological inflexibility-the inability to take value-based actions in the presence of unwanted thoughts, feelings, or bodily symptoms-is associated with negative health outcomes including depression and anxiety. We aimed to determine the association between the general construct of psychological inflexibility and pain intensity, and upper extremity physical function in patients with musculoskeletal illness in an orthopedics practice. We also set out to test multiple-mediator models proposing that psychological inflexibility affects pain intensity and upper extremity physical function directly, as well as indirectly through depression, anxiety, and pain catastrophizing. One hundred and eight patients with upper extremity illness completed self-report measures of pain intensity, upper extremity physical function, psychological inflexibility, pain catastrophizing, depression, and anxiety in this cross-sectional study. We found that psychological inflexibility affected pain intensity and upper extremity physical function directly and indirectly. Pain catastrophizing but not depression or anxiety mediated the association of psychological inflexibility to pain intensity and upper extremity physical function. Psychological inflexibility plays an important role in understanding the increased pain and decreased upper extremity physical function in patients with musculoskeletal pain. It also suggests that the cognitive error of pain catastrophizing is one of the mechanisms through which the general construct of psychological inflexibility may influence pain intensity and upper extremity physical function. Psychological treatments aimed at decreasing pain and increasing upper extremity physical function should target both pain catastrophizing and psychological inflexibility.