The persistence of lumbar somatic dysfunction and its association with bone mineral density.

CONTEXT Clinically meaningful somatic dysfunction, if left untreated, should persist over time and be associated with objective measurable findings. OBJECTIVE To investigate the persistence of lumbar somatic dysfunction over 8 weeks and the association of that persistence with lumbar bone mineral density (BMD) T scores. METHODS Individuals were assessed at 0, 4, and 8 weeks for the presence and severity of paraspinal tissue texture abnormalities (TTA), vertebral rotational asymmetry, anterior motion restriction, and tenderness from L1 to L4. Participants underwent dual-energy x-ray absorptiometry of the lumbar spine at 0 and 8 weeks. Persistent somatic dysfunction findings from all 3 examinations were compared with BMD T scores obtained at 8 weeks and to changes in the BMD T scores from 0 to 8 weeks. RESULTS Forty-eight individuals (38 women [79%] and 10 men [21%]) participated in the study. The mean (standard deviation [SD]) age was 30.1 (6.4) years (range, 20.0-40.8 years), and the mean (SD) body mass index was 26.3 (5.2). The percentage of vertebrae with persistent somatic dysfunction varied by vertebral level and ranged from 44% to 83% for TTA, 63% to 79% for rotational asymmetry, 10% to 56% for motion restriction, and 2% to 10% for tenderness. Vertebral segments with persistent motion restriction had higher mean BMD T scores (95% confidence interval [CI]) than those without persistent motion restriction (0.6 [0.4 to 0.8] vs 0.2 [0.1 to 0.4], respectively; P=.02). There was a significant increase in the vertebral BMD T scores for those vertebrae that demonstrated persistent TTA (P=.02) and for those vertebrae that demonstrated persistent moderate/severe TTA (P=.02). A significant difference was found in the initial to final vertebral BMD T-score change between vertebrae that demonstrated persistent tenderness and those that did not (mean [95% CI] change, -0.2 [-0.4 to 0.1] vs 0.1 [0.0 to 0.1], respectively; P=.04). CONCLUSION A persistence of predominantly left lumbar rotation was observed. Persistent vertebral motion restriction was shown to have an association with final lumbar BMD T scores, and persistent TTA and tenderness were associated with changes in the BMD T scores over 8 weeks.