The aim of this subproject is to investigate whether movement-related fear in patients with chronic primary low back pain (CPLBP) translates into discernable patterns of the patients’ movements and stress response during a range of standard tasks. Fear avoidance (FA) beliefs (i.e. movements may lead to pain/injury) motivate patients with CPLBP to avoid physical activity and may thereby contribute to the maintenance of pain and disability. Patients’ confrontation with unavoidable movements should act as a stressor and lead to psychophysiological stress responses (heart rate, skin conductance) and to a guarded task execution (EMG and movement patterns). The vast amount of FA research used self-report measures; few studies investigated neural or psychophysiological correlates but none integrated these parameters. This project will examine movement patterns and stress responses associated with FA and extend research on maladaptive appraisal of somatic symptoms and concomitant stress responses. We will investigate healthy persons and patients with CPLBP with high and low FA while they engage in standard back stressing tasks (e. g. lifting an object).