Fear-avoidance and endurance-related responses to pain: new models of behavior and their consequences for clinical practice.

OBJECTIVES Patients' beliefs and expectations about their pain have been identified as important disabling factors in chronic musculoskeletal pain. Besides fear-avoidance beliefs and pain-related fear, cognitions such as thought suppression as well as pain/task persistence behavior have been shown to be associated with pain and disability. The aim of this report is to present a critical evaluation of research, based on the avoidance-endurance model of pain. METHODS A qualitative review of the literature concerning the occurrence of fear-avoidance- versus endurance-related pain responses as well as concerning the association of these pain responses and different self-reported and overtly measured outcomes. RESULTS While consistent evidence has confirmed the role of fear-avoidance responses to pain and pain-related disability measured via self-report, the influence of fear-avoidance responses on objectively assessed physical activity is less clear. There is preliminary evidence that avoidance-endurance model based subgroups showing a pattern of cognitions of thought suppression, anxious/depressive mood and task/pain persistence behavior (distress endurance responses) or a pattern of cognitions of ignoring/minimizing pain, positive mood despite pain and task/pain persistence behavior (eustress endurance responses) will develop more pain prospectively and show higher levels of specific strain postures, measured by accelerometer, than patients showing adaptive pain responses. CONCLUSION Although both, fear-avoidance and endurance responses have been identified in patients with chronic musculoskeletal pain, currently evidence to confirm their hypothesized consequences for daily functioning is incomplete. Finally, thoughts on the development of differentially targeted and individually scheduled behavioral interventions are reported, including suggestions for further research.