Fear-Avoidance Beliefs, Coping und Biofeedback. Was wird bei der Entstehung und in der Behandlung chronischer Rückenschmerzen gelernt?

Learning is crucial for the development, maintenance, and treatment of mental disorders. The fear-avoidance model (Vlaeyen & Linton, 2000) is frequently used to explain the development and maintenance of chronic back pain through classical and operant conditioning procedures. However, inconsistent evidence about the presence of a conditioned fear response suggests further learning mechanisms to be important; especially in the formation of fear-avoidance beliefs. Cognitive-behavioral therapy offers a wide range of interventions in the treatment of chronic back pain. Depending on the intervention, the used methods and targeted therapy goals might differ, from reducing pain intensity to improving quality of life despite being in pain. First studies suggest that accommodative coping strategies might be more beneficial in the treatment of chronic pain compared to assimilative coping strategies. Adequate measurements are essential for investigating the used coping strategies as well as the consequences of their utilization on pain-related symptoms. Biofeedback has been found to be an effective psychological intervention in the rehabilitation of fibromyalgia, migraine, and tension-type headache. However, the empirical evidence in the treatment of chronic back pain shows inconsistent results and remains unclear. In this thesis, four Studies are presented that investigate said aspects. Despite their relevance in the development and maintenance of chronic back pain, there is little knowledge on the mechanisms behind the acquisition of fear-avoidance beliefs. On that account, in Study 1, we aimed at examining whether evaluative conditioning affected attitudes toward back-stressing movements as found in fear-avoidance beliefs. Results from two experiments showed that evaluative conditioning formed negative (but not positive) attitudes toward back-stressing movements on an explicit level and partially on an implicit level. Thus, our results indicate that evaluative conditioning might play a role in the acquisition of fear-avoidance beliefs. In Study 2, we developed a German version of the Pain Solutions Questionnaire (PaSol) and analyzed its psychometric properties in a sample of N = 165 patients suffering from chronic back pain. The exploratory factor analysis reproduced the original questionnaire’s four-factor structure. The reliability and validity analyses demonstrated acceptable to good results. Moreover, the PaSol was found to be sensitive to detect treatment changes over time. The German version of the PaSol is a reliable and valid instrument in the measurement of assimilative and accommodative coping strategies in patients suffering from chronic low back pain. In Study 3, we investigated the efficacy of biofeedback as treatment option for chronic back pain by conducting a meta-analysis based on 21 studies that employed a biofeedback intervention for at least 25 % of the total treatment time and reported at least one of the following outcomes: pain intensity, depression, disability, self-efficacy, and reduction of muscle tension. Effect size estimates for the total sample suggested a small to moderate effect for all outcomes. These effects remained comparatively stable over an average follow-up phase of 8 months and for controlled studies only. Thus, we conclude that biofeedback can be beneficial for various pain-related outcomes in the short and long terms. A further discussion on biofeedback as a psychological intervention, both as standalone and as adjunctive intervention for chronic back pain is shown in Study 4. Altogether, our results indicate that biofeedback can lead to improvements on several pain-related outcomes. However, our results also suggest the utilization of further interventions for highly disabled patients.