Meier ML, PhD, Hotz-Boendermaker S, PhD, PT, et al.

WFC 2013 AWARD WINNING PAPER. Neural Responses of Posterior to Anterior Movement on Lumbar Vertebrae: A Functional MRI Study. JMPT 2013; xx:1-10. Epub ahead of print.

Comments: This 2013 epub ahead of print paper documents that in the primary somatosensory cortex (postcentral gyrus (S1)) there is a significant bilateral neural response to thumb pressure applied in a posterior-to-anterior direction to the spinous processes of L1, L3, & L5 which was a distinctly different response than when the same pressure was applied to the Pt’s thumb based on MRI evaluation. In other words, the brain responds in a specific manner when P-A pressure is applied to vertebrae that is distinctive and may provide a method for studying the impact of both manipulation and back pain on brain function.

Background :Study to develop & test a clinically relevant method to mechanically stimulate lumbar functional spinal units while recording brain activity by means of fMRI. Ss were studied in t prone position w their face on a stabilization pillow wh was fixed to the MRI headrest & supporting straps were attached around shoulders to minimize mov’t. A manual therapist applied controlled, nonpainful P-A thumb pressure (30 N) to 10 healthy Ss at L1, L3, & L5 spinous processes. Pressure was applied to the Ss thumb in t control condition. Blood oxygenation level–dependent responses were analyzed in relation to the lumbar & thumb stimulations. The study conducted by the Chiropractic Department, Faculty of Medicine, University of Zürich, Switzerland.

Results: P-A pressure applied to the lumbar spinous processes demonstrated bilateral neural responses in medial parts of the postcentral gyrus (S1). Additional activity was seen in the secondary somatosensory cortex (S2), posterior parts of the insular cortex, different parts of the cingulate cortex, and cerebellum. Thumb stimulations revealed activation only in lateral parts of the contralateral S1.

Conclusion: The study demonstrates the feasibility of the application of P-A pressure on lumbar spinous processes in an MRI environment. This may be a promising tool for further investigations regarding neuroplastic changes in CLBP.