Physical activity and psychosocial characteristics of individuals with and without chronic low back pain in daily life: A study protocol for the PRIA intensive longitudinal study

Background: Despite the high prevalence of chronic low back pain (cLBP), its underlying mechanisms remain poorly understood. Addressing modifiable psychosocial resources and health behaviors such as physical activity offers a promising avenue for reducing the impact of cLBP. Furthermore, although the relationship between physical activity and pain is theorized 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. Methods: This prospective longitudinal study combines online questionnaires with Ecological Momentary Assessment (EMA) of health behaviors, 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, 3 and 6 months later (T1 and T2). A total of 230 participants (115 individuals with cLBP and 115 without cLBP) aged 18 to 64 years will be enrolled. The associations between cLBP and the measured parameters will be examined using multilevel models. Discussion: The use of ambulatory assessment to examine physical activity, psychosocial factors, back health and pain in individuals’ daily lives addresses the limitations of previous research based on cross-sectional designs. This approach is expected to provide novel insights into the intraindividual and temporal dynamics of pain, back health, physical activity and psychosocial risk factors and resources. These findings are expected to contribute to the development of improved diagnostics, recommendations and interventions that leverage advances in mobile technology for more personalized and effective prevention and healthcare solutions. Trial registration: This trial is registered in the German Clinical Trials Register, DRKS-ID DRKS00032978. Date of registration: 22 December 2022.