Ultrasound-assessed segmental lumbar motion and clinical outcomes following spinal manipulation: a randomized, controlled pilot study.

Abstract

Objective To determine if spinal manipulation (SM) leads to measurable changes in ultrasound-assessed segmental lumbar motion (SLM) compared with a sham intervention and to evaluate short-term effects on pain, trunk flexion, perceived recovery, and disability. Methods Forty-four adults with low back pain (LBP) were randomly assigned to receive either lumbar SM or a sham intervention. SLM was assessed using diagnostic ultrasound imaging by measuring distances between adjacent lumbar spinous processes (L1-L5) in the fully flexed position before and immediately after the intervention. Pain, trunk flexion, perceived improvement, and disability were assessed using the Numeric Pain Rating Scale, Oswestry Disability Index, Finger-to-Floor Test, and Global Rating of Change. Mixed-design analyses of variance were used to evaluate group-by-time effects for all outcomes. Results No significant group-by-time interaction was found for ultrasound-assessed SLM ( F (1,42)=0.001, p = 0.972) or finger-to-floor distance ( F (1,42)=0.91, p = 0.347), indicating no differential change between groups. For current pain intensity, a significant group-by-time interaction was observed ( F (2,84) = 4.39, p = 0.015), with greater reductions in the SM group. Disability also improved more in the SM group ( F (1,42) = 12.38, p = 0.001). No significant group-by-time interaction was found for perceived improvement ( F (1,42)=0.62, p = 0.434). Conclusion Lumbar SM produced significant short-term improvements in pain and disability compared with the sham manipulation, but these effects were not accompanied by a significant between-group increase in ultrasound-assessed SLM. These pilot findings suggest that immediate segmental motion changes are unlikely to explain the short-term clinical effects following SM in individuals with LBP. Clinical trailas registration no NCT06294132 (clinicaltrial.gov).