Evaluation of the effects of pulling angle and force on intermittent cervical traction. J Formos Med Assoc. 1991.
Examination of pull angle reveals neutral (less angulation) creates more separation at levels C4/5. +30ş pull angle separates C6/7 in comparison. In terms of force: above 30 pounds increased discomfort.

Cervical spine disorders. A comparison of 3 types. Spine. 1985. Static, intermittent & manual traction methods were assessed. Intermittent traction performed significantly better than the other methods.

Research on the effectiveness of intermittent cervical traction using short-latency somatosensory evoked potentials. J Ortho Sci 2002. Traction may improve conduction disturbance primarily by increasing the blood flow from the nerve roots to the spinal parenchyma.

Predictors of short term outcome with patients with cervical radiculopathy. Phys Ther 2006. A multi-modal approach, including cervical traction therapy showed significant short-term outcomes.

Cervical traction and thoracic manipulation for the management of mild cervical myelopathy from a herniated cervical disc. J Orth 2006. Cervical traction and thoracic manipulation seem useful for the reduction of pain scores and levels of disability in this condition.

Effects of intermittent cervical traction on muscle pain. EMG and flowmetric studies on cervical paraspinals. Nippon Med J 1994. Cervical intermittent traction was shown to be effective in relieving pain, increasing frequency of myoelectric signals and improving blood flow in effected muscles.

Stress in lumbar IVD during distraction: a cadavaric study. Spine 2007. Distraction appears to predictably reduce nucleus pressure. The effect of distraction on distribution of compressive stress may be dependant in part on the health (degeneration) of the disc

Analysis model simulating the correlation of cervical traction force with the pressure in the cervical nucleus pulposus. Di Xue Bao 2002. The exponential model best describes the trend in changes of the pressure reduction in the cervical nucleus in association with varied cervical traction forces.

Distraction of lumbar vertebra in gravitational traction. Spine 1998. Gravitational traction had a very apparent effect on intervertebral space and in distraction of the lumbar vertebra

Intermittent cervical traction: a progenitor of lumbar radicular pain. Arch Phys Med Rehab 1992. Moderate to severe degenerative changes in the cervical spine can create a cord tethering effect generating leg symptoms from cervical distraction.

Outcomes after prone lumbar traction protocol with activity limiting LBP: A prospective case series study. Arch Phys Med Rehab 2008. Traction applied in the prone position over an 8 week course of treatment was associated with improvements in pain intensity and disability scores in patients with ongoing LBP… Though a causal relationship between outcome and intervention cannot be made without further research.

Stress in lumbar IVD during distraction: a cadaveric study. Gay RE et al. Spine (11)1 2007. Distraction appears to predictably reduce nucleus pulposis pressure. That reduction is ultimately dependant on the health of the disc.

Trunk muscle respone to various protocols of lumbar traction. Cholewicki JE et al. Manual Therapy 1(5) 2008.
The authors used EMG to assess trunk muscle activity during various protocols of lumbar traction. There was minimal activity noted though greated sacrospinalis activity with thoracic bracing. A loss of trunk flexability noted post-treatment suggests increased intradiscal pressure from fluid in-flow which may be enhanced via intermittant protocols. The authors note LBP patients may gain relief during traction via adverse muscle co-activation patterns being reduced.

Cyclical tensile stress exerts a protective effect on the IVD. Sowa et al. Am J Phys Med Rehab (87) 2008 537-455. This in vitro study shows controlled, low level tensile stress (elongation) creates a potent anti-inflammatory, anti-catabolic effect on disc metabolism and may suggest a mechanism for relief of pain from traction/motion therapy. Motion may create an improved expression of catabolic agents

Intertester reliability and validity of motion assesment of lumbar spine/accessory motion testing. Landel et al. Phys ther 88;1. 2008 Another study showing the lack of any agreement from motion palpation tests. Further validation of the arbitrary nature of these tests but adding validity to the necessity of functional/provocative examination such as directional preference, form closure and force closure etc.

Segmental lumbar mobility in individuals with LBP: in vivo dynamic MRI. BMC Musculo Disord 2007 Jan;29(8). Persons with non-specific LBP have a tendency to have hypermobility of a lumbar segment vs. asymptomatic subjects. This, along with McGill’s shear instability testing adds further validity to form/force closure concepts and the importance of motion disorders concomitant with disc lesions.

Changes in spinal height following sustained lumbar flexion & extension postures; a measure of IVD hydration. JMPT 2009 Jun;32. Height recovery, which is directly related to disc hydration, is enhanced by both flexion & extension rest postures. Vicoelastic creep probable from water content changes in the nucleus are responsible.

Reliability of Chiropractic methods commonly used to detect manipulable lesion in patients with cLBP. JMPT 2000 May;23. The most widespread tests we use to discover the ‘subluxation’ come under fire once again. This study and many others draw us closer to the global, functional form/force closure and shear instability tests as far more valid than palpation, LLI or static film interpretation.

Intertester reliability and validity of motion assessments during lumbar motion testing. PT 2008 Jan;88. P-A testing of lumbar motion segments failed to agree with dynamic MRI findings further casting doubt that the painful segment is ‘fixed’ or hypo-mobile.

Quantitative changes in the cervical neural foramen resulting from axial traction: in vivo imaging. Spine 2008 Jul;8. During axial traction there is a significant increase in foramina size after ~12 pounds of applied traction. There was no signigicant size difference between 20-30 pounds of traction. This is another potential indicator for “less is more” or “more isn’t necessarily better” especially in terms of traction forcec.

The influence of cervical traction, compression and Spurling test on cervical IV foramen size. Spine 2009 Jul;15. A further study demonstrating the effect distraction and compression have on the foramen. Distraction at ~24 pounds of tension increased the foramen size in the mid-cervicals 120%..

McKenzie classification of mechanical spinal pain: profile of syndromes and directional preference. Man Ther 2008. An in-depth review reveals 140/187 cases were ‘disc derangement’ (reducible) with 11/187 irreducible. 98/140 were found to have an extension DP with 34/140 lateral or glides and 8/140 flexion. That translates to ~70-75% of cases demonstrating a reducible disc with an extension DP

Unloaded movement facilitation exercise compared to no exercise or alternative therapy for NscLBP. JMPT 2007 May;30. A systematic review reveals that LB strengthening exercise outcomes are comparable or less effective than McKenzie type facilitation motion and Yoga.

Interexaminer reliability of hip extension test for suspected impaired motor control of the lumbar spine. JMPT 2006 Jun;29. Murphy and assoc. demonstrate good reliability in this test in detecting lumbar spine deviation.

Motor control patterns during an Active straight leg raise in cPelvic pain. Spine 2009; 34(9). The motor control pattern identified by the ALR has the potential to be a primary mechanism driving ongoing pelvic pain and disability.

The twin spine study: contributions to a changing view of disc degeneration. Spine 2009 Jan;9. Sets of twins separated at birth and raised in variant cultures suggest disc degeneration is determined in great part by genetic influences and in small part by environmental factors including vibration and loading

Treating acute low back pain with heat wrap therapy and/or exercise. Spine 2005 Jul;5. When a directional preference was possible and heat used in conjunction a better than 80% improvement in pain relief was noted vs. the heat or exercise alone.

Slump stretching in the management of non-radicular LBP. Man Ther 2006. Cleland et al demonstrated that a certain class of patient; non-radicular LBP whose symptoms were tolerant to the seated slump stretch. At discharge patients given the slump had better centralization and symptom improvement.

A clinical prediction rule for classifying patients with LBP who demonstrate short-term improvement with mechanical traction. Eur Spine 2009 Apr;18. 4 clinical variables were identified improving the odds of improvement with traction from 20% to 70%. They were: non-involvement with manual labor, low FABQ, over 30 and no neurologic deficits. Only 3 sessions demonstrated good short-term relief at ~35% bdywgt traction force.

  • Long-term outcomes of surgical vs. non-surgical mangt. Of sciatica secondary to HNP: 10 year Maine Lumbar spine study. Spine 2005 Apr;15. This 10 year follow-up of surgical vs. non-surgical cases found 25% of surgical patients had under gone a second surgery and 25% of non-surgical had as well. Overall 69% of initial surgical patients reported improvement vs. 61% of non- surgical cases. (This further demonstrates that LBP is typically a life-long, on- going problem with little dramatic or consistent avenues for permanent relief).