Expectancies and functional impairment in chronic low back pain.

Perceived self-efficacy [2] and pain response expectancies [13] were examined as correlates of movement limitations and impaired functioning in a sample of 40 patients with chronic low back pain. Self-efficacy was operationalized as patients' ratings of their ability to perform movements, while response expectancies were operationalized as ratings of the degree of pain expected to accompany the movements. Patients predicted their ability to perform 10 simple movements and the degree of pain that would accompany each movement; on a separate occasion, subjects' actual performance of the movements was assessed. In general, independent predictions of both movement ability and pain correlated significantly with performance of specific movements as rated from videotapes. Total movement scores correlated 0.55 and -0.54, respectively, with total self-efficacy and pain response expectancy ratings. Expectancy ratings were also predictive of average daily pain ratings and questionnaire ratings of physical impairment in everyday life. Multiple regression analyses, including causal modeling, indicated that actual performance was best predicted by self-efficacy ratings, which in turn appeared to be determined by pain response expectancies.