Relationships Between Muscle Activity, Soft Tissue Changes, and Movement Strategies in Individuals With Chronic Low Back Pain

This study aims to explore, in patients with chronic non-specific low back pain (cnsLBP), the relationships between lumbar muscle activity, structural and morphological characteristics of the paraspinal muscles, and movement strategies, during a functional, ecological task: walking. To do this, we will compare a group of cnsLBP patients with a group of asymptomatic subjects, combining several types of measurements taken at different walking intensities: spinal kinematics (movement strategies), electromyographic activity of the lumbar muscles, and structural parameters of the paraspinal muscles (stiffness and thickness). The objective is twofold: first, to identify any significant differences between cnsLBP patients and healthy subjects on these combined parameters; second, to explore the interactions between these three dimensions (muscle activity, muscle structure, movement strategy) in order to better understand their relationships with pain and with how CNSLBP functions during physical activity. This multidimensional, ecological approach could also help identify subgroups within the cnsLBP population, reflecting the clinical heterogeneity already documented in the literature. Ultimately, the expected results will contribute to a better understanding of the biomechanical and neuromuscular mechanisms involved during physical activity in these patients, and will provide objective elements to help individualize physical activity recommendations according to each patient's profile.