Electromyogram diagnosed chronic lumbar radiculopathy is highly associated with L4-S1 regional multifidus atrophy on magnetic resonance imaging.

Modified Goutallier grading demonstrated 2% grade 0, 68% grade 1, 19% grade 2 and 11% grade 3 lumbar multifidus atrophy.

In the control cohort, 36% demonstrated grade 0, 43% grade 1, and 21% grade 2 lumbar multifidus atrophy, with no patients demonstrating grade 3 atrophy.

The prevalence of lumbar multifidus atrophy was significantly higher in the chronic lumbar radiculopathy cohort compared with symptomatic patients with normal electromyography findings.