Using MRI Scans to Evaluate Spinal Manipulation

Zygapophysial joints, better known as facet or "Z" joints, are located on the back (posterior) of the spine on each side of the vertebrae where it overlaps the neighboring vertebrae. Z joints provide stability and allow the spine to bend and twist. Adhesions in the Z joints may develop following hypomobility of vertebrae. These adhesions may be alleviated by separation (gapping) of the Z joints.

Side posture adjusting (spinal manipulation) is thought by many to gap the Z joints, yet no measurable differences of the Z joints before and after spinal manipulation have ever been published. This study will evaluate gapping of the L3/L4, L4/L5, and L5/S1 Z joints by taking measurements directly from MRI scans of the Z joints before and during positioning for a side posture adjustment, and before and after side posture adjusting.

Health volunteers will be randomly assigned to one of four groups: 1) neutral position followed by side posture positioning (trunk rotated to the volunteer's right); 2) neutral position followed by side posture spinal adjusting followed by neutral positioning; 3) neutral position followed by side posture spinal adjusting, followed by side posture positioning; and 4) neutral position followed by neutral position (control group). MRI scans will be taken with the volunteers in the original neutral position and in the final position (either second neutral position or side posture positioning).