Context: Identifying objective measures that correlate with somatic dysfunction palpatory findings will aid in establishing clinical relevance of the findings and provide outcome measures for future studies.
Objectives: To investigate the association of altered segmental lumbar vertebral mechanics (ie, somatic dysfunction) as assessed by palpation with bone mineral density (BMD) T-score variability in participants, some with chronic low back pain (CLBP) and others without low back pain (LBP).
Methods: Individuals with CLBP and individuals without LBP were examined by 2 blinded examiners for the presence or absence of paraspinal tissue texture abnormalities, vertebral rotational asymmetry, anterior motion restriction, and tenderness from L1 to L4. All participants then received a dual-energy x-ray absorptiometry scan of the lumbar spine. Bone mineral density T scores were compared between the CLBP and non-LBP groups.
Results: Sixty-three individuals (16 CLBP, 47 non-LBP) participated in the study. Lumbar segments with perceivable rotational asymmetry had higher mean BMD T scores (95% confidence interval [95% CI]) than lumbar segments with no asymmetry (0.5 [0.4-0.7] vs -0.2 [-0.6 to 0.2], respectively; P=.002). Additionally, lumbar segments with anterior motion restriction had higher mean BMD T scores (95% CI) than lumbar segments with no motion restriction (0.6 [0.4-0.7] vs 0.1 [-0.2 to 0.3], respectively; P=.03). Participants with CLBP demonstrated higher regional mean lumbar BMD T scores (95% CI) than those without CLBP (0.9 [0.6-1.1] vs 0.3 [0.2-0.5], respectively; P<.001). After accounting for sex and body mass index, vertebral segments with rotational asymmetry (in non-LBP participants only) and vertebral segments with motion restriction had higher mean BMD T scores than vertebral segments with no asymmetry or motion restriction.
Conclusions: Participants with CLBP had significantly higher lumbar BMD than participants without LBP. The presence of rotational asymmetry or motion restriction was associated with elevated BMD at the affected vertebrae.