Biomechanical optimization of rolling manipulation for lumbar muscle strain: a study protocol of cerebral hemodynamic...

Lumbar muscle strain (LMS) is a common chronic soft tissue injury disorder, and Tuina, especially Tuina rolling manipulation, is widely used for its management. However, standardized force parameters based on biomechanical effects have not yet been established, and the analgesic mechanisms of rolling manipulation remain insufficiently understood, particularly regarding its influence on cortical hemodynamic responses during manual intervention. Existing studies are fragmented, lacking systematic investigation of the entire chain from pain stimulation-induced cortical hemodynamic responses, to biomechanically optimized manipulation parameters, and to clinical efficacy. Therefore, this study aims to combine functional near-infrared spectroscopy (fNIRS) with biomechanical detection to explore cortical hemodynamic changes induced by pain stimulation, determine the optimal pressure parameters of rolling manipulation and explore the cortical hemodynamic responses associated with rolling manipulation treatment for lumbar muscle strain.

This is a three-part, hierarchical mixed-methods study. Part 1 (Observational): We will compare cerebral hemodynamic responses (via fNIRS) between LMS patients (n = 15) and healthy controls (n = 15) under two levels of controlled pain stimulation (pain-free vs. high pain threshold). Part 2 (Interventional, Crossover): In 24 LMS patients, we will screen for the optimal pressure level (low, medium, high) of rolling manipulation by evaluating multi-dimensional biomechanical outcomes. Part 3 (Interventional, Controlled): Using the optimal pressure identified in Part 2, we will enroll 69 participants in total, including 46 patients with LMS (23 in the case intervention group and 23 in the case control group) and 23 healthy controls.fNIRS will be used to characterize cortical hemodynamic changes associated with rolling manipulation, while clinical and biomechanical outcomes will be assessed to evaluate therapeutic effects after two treatment courses.

This protocol combines neuroimaging and biomechanical assessments to explore the potential association between peripheral biomechanical responses and cortical hemodynamic changes during Tuina rolling manipulation, optimize key operational parameters, and provide preliminary evidence for future clinical research and application.