Abstract:Background and objective: Several cognitive-behavioral factors contribute to the persistence of pain disability in patients with chronic back pain. Fear-avoidance beliefs and fear of movement/(re)injury in particular have been shown to be strong predictors of physical performance and pain disability. Patients reporting substantial pain-related fear might benefit from exposure in vivo to a set of individually tailored, fear-eliciting, and hierarchically ordered physical movements rather than more general graded activity.Patients and interventions: Six consecutive patients with chronic low back pain who reported substantial fear of movement/(re)injury were included in the study. After a no-treatment baseline measurement period, the patients were randomly assigned to one of two interventions. In the first intervention, patients received exposure in vivo first, followed by graded activity. In the second intervention, the sequence of treatment modules was reversed. Before each treatment module, treatment credibility was assessed. Daily measures of pain-related fear, pain catastrophizing, and pain intensity were completed using visual analog scales. In addition, standardized measures of pain disability, pain-related fear, and pain vigilance were taken before and after each treatment module and at the 1-year follow-up. To obtain more objective data on actual activity levels, an ambulatory activity monitor was carried by the patients during 1 week before and after each treatment module.Results: Time series analysis of the daily measures showed that improvements in pain-related fear and pain catastrophizing occurred only during the exposure in vivo and not during the graded activity, irrespective of the treatment order. Analysis of the pretreatment to post-treatment differences also revealed that decreases in pain-related fear also concurred with decreases in pain disability and pain vigilance and an increase in physical activity levels. All improvements remained at the 1-year follow-up.Key Words: Anxiety-Cognitive-behavioral treatment-Exposure in vivo-Fearavoidance beliefs-Low back pain.The early notion that, in chronic patients, the lowered ability to accomplish tasks of daily living is merely the consequence of pain severity has now been reconsidered. Indeed, a steadily increasing number of studies are showing that observable physical performance and selfreported disability levels in subacute and chronic pain are associated with cognitive and behavioral aspects of