Z-Joint Changes in Low Back Pain Following Adjusting
Condition: Mechanical Low Back Pain
MeSH terms: Back Pain; Low Back Pain
Study type: Interventional

Summary: 
      The purpose of this continuation project is to use MRI to evaluate gapping of the
      zygapophysial (Z) joints following side-posture positioning and side-posture spinal adjusting
      in subjects with acute low back pain.
    

Detailed description: 
      The purpose of this continuation project is to use MRI to evaluate gapping of the
      zygapophysial (Z) joints following side-posture positioning and side-posture spinal adjusting
      in subjects with acute low back pain (LBP). A fundamental hypothesis of one of the beneficial
      effects of chiropractic spinal adjusting is that adhesions, developing in the Z joints
      following hypomobility of these structures, are thought to be alleviated by separation
      (gapping) of the Z joints through spinal adjusting. In the previous study, side-posture
      adjusting was found to gap the Z joints in healthy subjects. The aim of this study is to
      determine if differences can be measured in the L4/L5 and L5/S1 Z joint spaces during
      side-posture positioning and after lumbar side-posture spinal adjusting of 112 subjects with
      acute LBP, and to determine if the amount of gapping is related to pain relief and improved
      function. Before any treatment begins, the subjects will be temporarily randomized into one
      of 4 MRI groups: 1) neutral positioning, followed by side-posture positioning (most painful
      side up); 2) neutral positioning, followed by side-posture adjusting (most painful side up),
      followed by neutral positioning; 3) neutral positioning, followed by side-posture adjusting
      (most painful side up) and remaining in side-posture; and 4) (pure control group) neutral
      positioning, followed by very brief side-posture positioning, followed by neutral
      positioning. MRI scans will be taken with the subjects in the original neutral position and
      in the final position. Both MRI scans will be conducted consecutively over approximately 30
      minutes (12:19 minutes per scan). All spinal adjustments given during this appointment will
      be performed directly on the MRI gantry table after the first scan. A second MRI appointment
      will occur 2 weeks later, after 2 weeks of treatment. At the second MRI appointment, subjects
      will be assigned to the MRI group opposite to the one to which they were randomized during
      the first MRI appointment. Three observers, blinded to each other and to subject grouping,
      will make anterior-to-posterior measurements (A-P gap) of the Z joints directly from the MRI
      scans. The gapping difference between the second and first scans of each MRI appointment will
      be analyzed to determine if differences exist between the 4 groups. Results of the first and
      second MRI appointments will also be evaluated to determine if the amount of gapping is
      related to pain (at first MRI appointment), relief of pain (at the second MRI appointment -
      difference in Visual Analog Scale from initial exam to MRI appointment) and current (first
      MRI appointment) and change in disability (second MRI appointment - difference in Bournemouth
      Questionnaire scores). The results of this study will be used to increase understanding of
      the mechanism of action of lumbar side posture adjusting and side-posture positioning in
      acute LBP patients.
    

Intervention name(s): Low back adjustment and MRI; Low back adjustment and MRI; MRI
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): Subjects received a 15 minutes MRI in neutral position, a chiropractic low back spinal manipulation, and a second 15 minute MRI in neutral position.; Subjects received a 15 minutes MRI in neutral position, a chiropractic spinal manipulation to the low back, and a second 15 minute MRI in a side posture position.; Subjects received a 15 minute MRI in neutral position and a second 15 minute MRI in neutral position.
Other intervention name(s): spinal manipulation = spinal adjustment; spinal manipulation = spinal adjustment; spinal manipulation = spinal adjustment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: spinal manipulation, zygapophysial joints