Optimization of Lumbar Sensory Stimulation Parameters in Office Workers With Chronic Low Back Pain

This study aims to determine the optimal parameters of lumbar sensory stimulation in office workers with chronic nonspecific low back pain. Participants will attend two laboratory sessions. The first session will characterize baseline clinical and sensorimotor function using clinical assessments, transcranial magnetic stimulation, functional near-infrared spectroscopy during unstable sitting, inertial measurement units, decomposition electromyography, and rehabilitative ultrasound imaging. The second session will use a randomized within-participant crossover design in which participants receive eight combinations of lumbar vibration frequency, amplitude, and direction while bilateral primary somatosensory cortex hemodynamic responses are continuously measured using functional near-infrared spectroscopy. The primary objective is to identify vibration parameters that produce a favorable and consistent cortical response while meeting predefined comfort, safety, and technical criteria.