Despite the high prevalence of chronic low back pain (cLBP), its underlying mechanisms remain poorly understood. Addressing modifiable psychosocial resources and health behaviours such as physical activity offers a promising avenue for reducing the impact of cLBP. Furthermore, although the relationship between physical activity and pain is theorised as a within-person process, previous research has primarily focused on between-person differences. In this article, we present the protocol for the prospective observational study PRIA (Psychologie und Rückengesundheit im Alltag), which is part of a larger interdisciplinary research consortium investigating preventive, diagnostic and therapeutic aspects of cLBP. Drawing on theories from health and pain psychology, the outlined study examines the interplay between different dimensions of cLBP and back health, physical activity and their psychosocial determinants within individuals in their everyday lives.

This prospective longitudinal study combines online questionnaires with ecological momentary assessment of health behaviours, cognitions, affect, social support and pain using a smartphone-based app (movisensXS) and continuous measurement of physical activity by accelerometry (movisens Move 4). Parameters will be recorded at baseline (T0), daily for the following 14 days (five times per day at 09:00, 12:00, 15:00, 18:00 and 21:00, resulting in up to 70 measurement occasions), 3 and 6 months later (T1 and T2). A total of 230 participants (115 individuals with cLBP and 115 without cLBP) aged 18–64 years will be enrolled. The associations between cLBP and the measured parameters will be examined using multilevel models.

The university’s ethics committee at the MSB Medical School Berlin approved the study on 8 March 2021 (approval number MSB-2021/59, amendment approved on 10 November 2023, amendment number MSB-2023/145). Ethical approval for the FOR 5177 initial screening was granted by Charité – Universitätsmedizin Berlin (EA1/058/21). All participants provided written informed consent. The results of this research will be published in peer-reviewed international journals, presented at national and international conferences, and reported to the German Research Foundation.

DRKS00032978.