The primary objective of this study is to investigate the effect of HD-tDC on EIH in individuals with CLBP. The secondary objective is to explore the potential neural imaging mechanisms underlying this effect through functional near-infrared spectroscopy (fNIRS)
This study is designed as a prospective, single-center, single-blind, randomized, parallel-controlled trial. Randomization was stratified by center in a 1:1 ratio, with a total of 46 participants enrolled, who were then randomly assigned to either the active HD-tDCS combined with moderate-intensity aerobic exercise group or the sham HD-tDCS combined with moderate-intensity aerobic exercise group.
The results of the intergroup analysis indicate that, compared to the Sham group, the Active group participants exhibited a significant statistical difference in ΔPPT at the third lumbar vertebra (P=0.007), while no significant statistical difference was observed at the fifth lumbar vertebra (P=0.6064), where Δ represents the difference before and after the intervention. The results of fNIRS indicate that the analysis of activation levels in pain-induced brain regions reveals that intergroup comparisons demonstrate a significant reduction in the concentration of oxyhemoglobin in the primary somatosensory cortex, dorsolateral prefrontal cortex, and frontal pole in the active group post-intervention (P0.05).
Our study confirms that HD-tDCS can enhance the EIH in patients with CLBP and reduce the level of activation in brain regions during pain induction.
The findings will advance the application of the EIH mechanism in the field of pain management, providing a theoretical basis for optimizing exercise analgesia protocols and conducting preliminary explorations for the formulation of personalized exercise prescriptions for chronic pain conditions in clinical settings.
Exercise-induced hypoalgesia
Chronic low back pain
