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(549) Relationships among fear of pain and movement, strength test performance, and indicators of hypothalamic pituitary adrenal axis (HPA axis) activity

      Two studies were located that tested associations between fear of pain and movement and performance during strength testing. They reported mixed results. In this study, we advance the literature by incorporating measures of Hypothalamic Pituitary Adrenal (HPA) axis activity – cortisol and blood pressure, which we collected directly before upper extremity strength tests. During a single session, healthy, upper-body untrained participants (N = 32, 46.9% women, 78% Caucasian, 24 yrs old (SD = 5.18)) completed measures of fear of pain and movement and pain catastrophizing before two consecutive strength tests using the non-dominant elbow flexors. Immediately before the strength tests, we collected blood pressure readings and saliva via an oral swab for cortisol. We also recorded perceived exertion, pain intensity, pain unpleasantness, and force output during the strength tests. Contrary to our hypotheses, we detected no significant associations among fear of pain and movement and cortisol, blood pressure, perceived effort, pain, or force output. However, systolic and diastolic blood pressure and perceived effort positively correlated with force output (r’s = .49 - .61, p < .01; r’s = .57 - .60, p < .01; r’s = .35 - .42, p < .05). In addition, the total score of the Pain Catastrophizing Scale (PCS) and rumination subscale of the PCS inversely correlated with force output (r’s = -.37 - -.40, p < .04; r’s = -.42 - .46, p < .02). These results support that pain catastrophizing is more strongly related to force output than fear of pain and movement, but none of the psychological constructs were significantly associated with indicators of HPA axis activity. Future studies should test relationships among these variables in samples with clinical pain, conduct alternative types of strength and function tests, and administer other HPA measures such as the corticotropin-releasing hormone challenge test.