Does task-and context-specific fear of movement play a role in the development and persistence of pregnancy-related lumbopelvic pain?: Study protocol

Abstract

Introduction Pregnancy-related lumbopelvic pain (PLPP) affects up to 90% of pregnant women and may persist for years postpartum but its multifactorial causes are poorly understood [1]. Incorporating a biopsychosocial framework may help unravel why PLPP develops and persists. The Fear-Avoidance Model of Pain proposes that pain-related beliefs, rather than pain itself, influence recovery. In the general low back pain population, fear of movement (FoM) has been identified as a key mechanism in pain persistence. Associations between FoM and PLPP prevalence have also been observed with studies relying on generic questionnaires to assess FoM [2]. However recent studies suggest that FoM can be highly task- and context-specific: individuals may only fear certain activities in certain contexts, which generic questionnaires may miss [3]. This study aims to (1) characterise the activities during which pregnant women with PLPP have a reluctance to move and compare these to activities reported by those without PLPP, (2) explore associations between task- and context-specific FoM, fear-avoidance beliefs, pain catastrophising, depression, and anxiety in women with PLPP, and (3) determine if task- and context-specific FoM predicts the onset and persistence of PLPP. Methods This protocol is part of the PROFit study (G0A1N24FWO/S69463). We will recruit 211 pregnant women without PLPP in the 1st trimester and follow them up in the 3rd trimester, 6 weeks and 9 months postpartum. PLPP will be assessed via self-report and clinical tests; task- and context-specific FoM by scoring the level of reluctance to perform self-selected activities; and (pain-related) psychological factors using validated questionnaires. Descriptive statistics and group comparisons, correlations, and logistic regression will address the three objectives. Results By 12 Nov. 2025, 27 participants (mean age=31.0, SD=3.6) were included. We hypothesize that pregnant woman with PLPP are more reluctant to perform activities involving their lower back and/or pelvic girdle, and that higher FoM will be associated with greater fear-avoidance beliefs, pain catastrophising, depression and anxiety. Lastly, we expect elevated FoM to predict the onset and persistence of PLPP. Process evaluation Participant recruitment is the biggest challenge of this study. Conclusion This study aims to understand the role of task- and context-specific FoM in the onset and persistence PLPP, supporting better prevention and treatment strategies.