Chiropractic + Naturopathic Doctor

Research Review Corner: May 2011

Shawn Thistle   

Features Research

Study title: Zygapophyseal joint adhesions after induced hypomobility
Authors: Cramer GD et al.
Publication information: Journal of Manipulative & Physiological Therapeutics 2010; 33: 508-518.

Study title: Zygapophyseal joint adhesions after induced hypomobility
Authors: Cramer GD et al.
Publication information: Journal of Manipulative & Physiological Therapeutics 2010; 33: 508-518.

Recently, Research Review Service released a free bonus update containing brief summaries of 20 studies that were not reviewed in full for subscribers to the service in 2010. Below is a  short excerpt from this document. 


One theoretical mechanism of putative biomechanical/anatomical beneficial effects of spinal manipulation is that facet joints become hypomobile for a variety of reasons (for example, sedentary lifestyle, repetitive occupation related activities, etc). The hypomobility can result in the development of intra-articular adhesions and degenerative changes in the facets. Spinal manipulation, or adjusting, is thought to gap facet joints and break up these adhesions. This is thought to slow the degenerative processes in the hypomobile joints. 

Adhesions have been previously identified in many hypomobile joints, but not in the facet joints of the spine. Therefore, the objective of this study was to determine if connective tissue adhesions developed in lumbar facet joints after induced intervertebral hypomobility (segmental fixation).

The authors used an established rat model in which three contiguous segments (L4, L5, L6) were fixed with specially engineered, surgically implanted, vertebral fixation devices. Facet joints of experimental rats (17 rats, 64 facet joints) with four, eight, 12 or 16 weeks of induced hypomobility were compared with joints of age-matched control rats (23 rats, 86 joints).

Small and medium adhesions were found in rats from all study groups. However, large adhesions were found only in rats with eight, 12, or 16 weeks of experimentally induced intervertebral hypomobility. Significant differences among study groups were found for small, medium and large adhesions. The average number of medium and large adhesions per joint increased with the length of experimentally induced hypomobility in rats with eight and 16 weeks of induced hypomobility.

This study produced some interesting results, but readers should keep some important limitations in mind:

  1. This was done in an animal model only; and
  2. complete immobility, as induced in this study, does not represent normal spinal loads, even in very sedentary humans.

These findings are consistent with the hypothesis that joint hypomobility leads to increased adhesion development. The results of this study are also consistent with previously reported findings.  Additional research is needed to determine the clinical significance of both adhesion size and the effects of spinal manipulation on facet joints. The authors mention that experiments assessing the effects of standardized high-velocity, low-amplitude thrusts and low-velocity, variable amplitude mobilizations on degenerative changes of the facet joints in this animal model are currently underway.

To download the full document, visit or e-mail Dr. Thistle –

Dr. Shawn Thistle is the founder and president of Research Review Service Inc., an online, subscription-based service designed to help busy practitioners to integrate current, relevant scientific evidence into their practice. Shawn graduated from CMCC and holds an Honours Degree in Kinesiology from McMaster University. He also holds a certificate in Contemporary Medical Acupuncture from McMaster University, and is a Certified Active Release Techniques (ART®) Provider. For more information about the Research Review Service, visit

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