Mechanical diagnosis and therapy as a clinical diagnostic approach in lumbar disc herniation: association with radiological findings

Background Lumbar disc herniation (LDH) is a leading causes of low back pain (LBP). Conservative approaches, such as the McKenzie Method of Mechanical Diagnosis and Therapy (MDT), are widely used as first-line treatments. MDT is based on patients’ symptomatic and mechanical responses to repeated movements and sustained postures. Although not pathology-specific, it is commonly applied to LDH. However, the association between radiological and mechanical characteristics remains unclear.Objectives To examine the association between MRI-based LDH classification and directional preference (DP) identified using MDT.Method This cross-sectional study included 120 individuals with LBP lasting more than four weeks and confirmed LDH. Data collection included demographic and clinical variables MRI findings, and MDT assessment to determine DP through repetitive lumbar movements. Disc herniations were classified as bulging, protrusion, extrusion, or sequestration.Association between disc tyoe and DP were analyzed using Pearson’s chi-square test.Results In total, 120 participants (59 females, 61 males; mean (SD) age = 44.14 (10.80) years) were enrolled. Protrusion was the most prevalent disc type (54.17%), and extension was the most frequently identified DP (49.16%). The results of this study demonstrated a significant association between disc type and DP (p < 0.001), with a strong effect size (Cramér’s V = 0.51).Conclusions A significant association exists between radiological and mechanical features in LDH. Extension DP was more common in milder cases, whereas many severe cases lacked a clear DP, suggesting MDT may be more responsive in less severe LDH. Further longitudinal studies are warranted.