Abstract
Objective: The multifidus muscle is closely related to lumbar spondylolysis and chronic low back pain; however, no studies have specifically examined its morphology in athletes engaged in rotation-related sports (RRS). This study aimed to investigate the association between multifidus muscle asymmetry, a history of lumbar spondylolysis, and chronic low back pain after returning to competition.
Methods: This study included 30 athletes: 10 track and field athletes (non-RRS) and 20 RRS athletes (10 with and 10 without a history of lumbar spondylolysis). The cross-sectional area of the multifidus muscle was measured using ultrasound, and the left-to-right ratio was calculated. The Kruskal-Wallis test was used to confirm the difference between non-RRS, RRS without a history of lumbar spondylolysis and RRS with a history of lumbar spondylolysis.
Results: The RRS group showed significantly higher left-right asymmetry than the non-RRS group (p＜0.01), and there was no statistically significant difference in the absolute cross-sectional areas between the sides. Among the RRS athletes with a history of lumbar spondylolysis, those with chronic lower back pain had a significantly greater left-right ratio than those without pain (p＜0.05).
Conclusion: These findings suggest that participation in RRS may influence multifidus muscle asymmetry, and that greater asymmetry may be associated with chronic lower back pain following lumbar spondylolysis. The results of the present study suggest that, in athletic settings, regular monitoring of multifidus muscle asymmetry and trunk muscle training when substantial asymmetry is detected may be associated with low back pain prevention and performance maintenance.
