The association of lower trunk muscle strength with low back pain in elite lightweight judokas is dependent on lumber spine abnormalities.（査読付）

Isokinetics and Exercise Science

Background: Lumbar radiological abnormalities (LRA) and trunk muscle weakness are major causes of the low back pain (LBP). We reported that the prevalence of LRA was approximately 90% in middle- and heavyweight-judokas, independent to the occurrence of LBP. However, the trunk muscle weakness, especially the rotators, plays a key role in occurrence of LBP in heavyweight judokas.
Objective: To examine the trunk muscle strength (TMS) and LRA impact on LBP occurrence in lightweight judokas.
Method: The strength of the trunk extensors, flexors, and rotators was measured in 32 lightweight male judokas. LBP and LRA were identified using a questionnaire, X-ray, and MRI.
Results: The occurrence rate of LBP and LRA were 40.6% and 62.5%, respectively, without any significant correlation. Among judokas without LRA, TMS of those with LBP were significantly lower than those without LBP (P < 0.05, the extensor; 60°/s: ES [d] = 1.38, 90°/s: ES [d] = 0.78, and 120 °/s: ES [d] = 0.37, flexor; 60°/s: ES [d] = 1.48, dominant rotator; 60°/s: ES [d] = 1.66, and 90 °/s: ES [d] = 1.87, non-dominant rotator; 90 °/s: ES [d] = 0.17, and dominant/non-dominant rotator ratio; 90 °/s: ES [d] = 1.55). Moreover, there were significant negative correlations between LBP severity and TMS (P<0.05, the extensor; 90°/s: r=−0.63, dominant rotator; 90°/s: r=−0.648, and dominant/non-dominant rotator ratio; 90°/s: r=−0.621) in judokas without LRA.

Okada T, Iwai K, Hakkaku T,  Nakazato K.

vol.30, pp.177-186, 2022