Beneficial effects of Chinese martial arts on the lumbar spine: A case series analysis of intervertebral disc, paraspinal muscles and vertebral body

Purpose: Chinese Martial arts is becoming increasingly prevalent worldwide. There is insufficient evidence to prove the health effects of martial arts due to methodological weaknesses. The aim of this study was to better understand the effects of Chinese martial arts on the skeletal and muscular status of the lumbar spine by quantitative magnetic resonance imaging (MRI).Methods: Nine elite martial arts athletes, eighteen amateurs, and eighteen sedentary volunteers underwent T2 mapping and q-Dixon imaging of the lumbar spine on a 3T (Tesla) system. T2 (Transverse) relaxation times were measured in different regions of interest of the intervertebral disc (IVD). Fat Fraction (FF) was measured in the paraspinal muscles and vertebral body.Results: Compared to the sedentary controls, martial arts athletes showed: (1) increased T2 times in the nucleus pulposus, especially in the central nucleus pulposus (P = 0.004); (2) decreased FF in the multifidus and erector spinae (all P < 0.04), and increased cross-sectional area in the psoas, quadratus lumborum, and multifidus (all P < 0.03); (3) decreased FF in vertebral body (P = 0.001). There was no significant difference in all quantitative MRI parameters between athletes and amateur enthusiasts. Besides, paraspinal muscle FF was negatively correlated with IVD T2 times (rho =-0.221; P = 0.014) and positively correlated with vertebral body FF (rho = 0.314; P < 0.001).Conclusions: Chinese martial arts has a positive effect on lumbar tissues, manifesting as better disc hydration, paraspinal muscle hypertrophy and reduced fat infiltration, and lower vertebral body fat content. Our study suggests a possible mechanism: martial arts practice enhances paraspinal muscles to maintain spinal stability, indirectly contributing to slowing down bone marrow conversion and promoting IVD hydration.