Magnetic Resonance Imaging Zygapophyseal Joint Space Changes (Gapping) in Low Back Pain Patients Following Spinal Manipulation and Side-Posture Positioning: A Randomized Controlled Mechanisms Trial With Blinding

Abstract

Objective The purpose of this study was to quantify lumbar zygapophyseal (Z) joint space separation (gapping) in low back pain (LBP) subjects after spinal manipulative therapy (SMT) or side-posture positioning (SPP). Methods This was a controlled mechanisms trial with randomization and blinding. Acute LBP subjects (N=112, four n=28 MRI protocol groups) had 2 magnetic resonance imaging (MRI) appointments (initial enrollment [M1] and following 2 weeks of chiropractic treatment [M2]; receiving 2 MRI scans of the L4/L5 and L5/S1 Z joints at each MRI appointment. After the first MRI scan of each appointment, subjects were randomized (M1 appointment) or assigned (M2 appointment) into SPP (non-manipulation), SMT (manipulation), or control MRI protocol groups. After SPP or SMT, a second MRI was taken. The central anterior-posterior (A-P) joint space was measured. Difference between most painful side A-P measurements taken post- and pre-intervention was the Z joint “gapping difference.” Gapping differences were compared (ANOVA) among protocol groups. Secondary measures of pain visual analog scale (VAS), verbal numeric pain rating scale (VNPRS), and function Bournemouth questionnaire (BQ) were assessed. Results Gapping differences were significant at the first (adjusted, p=0.01; SPP=0.66 +0.48mm; SMT=0.23 +0.86; control=0.18 +0.71) and second (adjusted, p=0.0005; SPP=0.65 +0.92mm, SMT=0.89 +0.71; control=0.35 +0.32) MRI appointments. VNPRS differences were significant at first MRI appointment (p=0.04) with SMT showing the greatest improvement. VAS and BQ improved after two weeks of care in all groups (both p<0.0001). Conclusions SPP showed greatest gapping at baseline. After two weeks, SMT resulted in greatest gapping. SPP appeared to have additive therapeutic benefit to SMT.

Effects of Axial Torsion on Disc Height Distribution: An In Vivo Study

“…19, 21–24 Greater unilateral change in facet spacing distance, 18, 25 as measured with MRI immediately following manipulation, have been reported. Joint gapping was coincident with significant pain reduction and suggests a relative asymmetric displacement.…”

Neural responses to the mechanical characteristics of high velocity, low amplitude spinal manipulation: Effect of specific contact site

“…Utilization data indicate most patients who receive spinal manipulation receive a manual procedure relatively high in velocity and low in amplitude (HVLA-SM) (Shekelle et al, 1992; Eisenberg et al, 1998; Christensen et al, 2005). Following preloading of the spinal tissues, the clinician rapidly delivers a thrust to a target vertebra through a short lever arm by manually contacting the skin overlying that vertebra’s lamina, spinous, transverse or mammillary process, with the intent of displacing the vertebra, gapping its facet joints, and creating mechanical, neurological and biological effects (Greenman, 1989; Hooper, 2005; Bergmann, 2005; Cramer et al, 2013; Leach, 2004). …”

A Feasibility Study to Assess Vibration and Sound From Zygapophyseal Joints During Motion Before and After Spinal Manipulation

“…The Z joint movement (gapping) produced by SMT 17,37 may have added sufficient mobility to the pre-SMT crepitus-producing joints that they moved more freely and did not produce crepitus post-SMT. Contrariwise, the SMT force on pre-SMT non-crepitus producing joints that were somewhat hypomobile, may have induced enough motion that they began to move into a range that had not been used immediately pre-SMT, consequently the joint surfaces may have been contacting in facetal areas that were not as well lubricated (i.e., less synovial fluid in these regions) as the more frequently used facetal regions, thus creating crepitus as the joints entered the previously hypomobile zones.…”

“…Those who passed the initial screening were scheduled for an examination where a research chiropractic physician conducted a thorough history and physical examination that included orthopedic and neurological tests to ensure subjects were selected who met stringent inclusion and had none of the exclusion criteria. Separate criteria that had been previously developed and implemented for healthy 19,20 and LBP subjects 37 were used in this study. Generally, healthy subjects had no current LBP, known spinal pathology, or spinal surgery; and no previous history of LBP lasting more than 2 weeks, or no more than 3 episodes of LBP of brief duration (one week) in any given year.…”