The cause of scoliosis is currently unknown and has been widely debated over the last several decades. Hormonal, metabolic, and structural causes have all been explored and validated to varying extents. At this point it is logical to conclude that it is likely a combination of these factors.
Despite the lack of a concrete cause of scoliosis, there are several factors that are well known to increase, or worsen, a scoliosis. One of these ‘progression factors’ seems to be the loss of the normal curve in the neck. Figure 1 illustrates the normal side view of the neck, or cervical spine. There should normally be a forward curve measuring approximately 35-45 degrees1,2. A recent study by Morningstar and Stitzel3 showed that people with moderate to severe scoliosis were far more likely to have lost the normal curve in their necks than people with mild scoliosis. Those with moderate or severe scoliosis had a loss of cervical curve 88% of the time, compared to only 55% of those with mild scoliosis, defined as a scoliosis below 30 degrees, which is often the threshold before conventional treatment (bracing) is initiated. Not only did they not have the normal neck curve, it was often backwards. A backwards curve in the neck is very problematic because it creates a vertical stretch on the spinal cord, which can then cause subsequent neurological deficits throughout the body.4 A normal curve in the neck tends to maintain the normal thoracic (mid back) curve, and increasing the neck curve leads to increasing thoracic (mid back) curve.5
Figure 1
Based upon this data, it is conceivable that scoliosis may be more effectively managed when steps are taken to promote a restoration of the normal neck curve. This component is often missing from many exercise-based treatment plans and may be the missing ingredient for sustained scoliosis improvement and correction. Early data suggests that exercise-based treatments focusing on the neck curve and profile of the spine may provide sustained scoliosis correction years later6,7.
Figure 28
Figure 2 above shows how a change from a normal neck curve (right image) to a backwards neck curve (left image) creates increased tension on the spinal cord and nerve roots. This causes distortion in the spinal cord, which may compromise normal neurologic function in the long spinal cord pathways. Increased spinal cord tension has also been implicated as a contributing cause of scoliosis. This tension prevents the spinal cord from lengthening during periods of skeletal growth, and therefore the spinal vertebrae must adapt to the functionally shortened spinal cord, which may lead to the spine curving or winding down upon itself so as not to further increase the tension on the spinal cord.
It is important to note that not all exercise-based treatment plans give priority to the involvement of the neck curve and sagittal profile. There are many types of exercise-based scoliosis treatment and anyone considering these treatments is advised to do their homework before selecting a treatment appropriate for them.
References
- Harrison DD, Janik TJ, Troyanovich SJ, Harrison DE, Colloca CJ. Evaluation of the assumptions used to derive an ideal normal cervical spine model. J Manipulative Physiol Ther. 1997 May;20(4):246-56.
- Kapandji IA. The Physiology of the Joints, Vol 3: The Trunk and Vertebral Column. 1974 Churchill Livingstone
- Morningstar MW, Stitzel CJ. The Relationship between cervical kyphosis and idiopathic scoliosis. J Vertebral Subluxation Res. October 13, 2008; 1-4.
- Harrison DE, Cailliet R, Harrison DD, Troyanovich SJ, Harrison SO. A review of biomechanics of the central nervous system–Part III: spinal cord stresses from postural loads and their neurologic effects. J Manipulative Physiol Ther. 1999 Jul-Aug;22:399-410.
- Erkan S, Yercan HS, Okcu G, Ozalp RT. The influence of sagittal cervical profile, gender and age on the thoracic kyphosis. Acta Orthop Belg. 2010 Oct;76(5):675-80.
- Morningstar MW. Outcomes for adult scoliosis patients receiving chiropractic rehabilitation: a 24 month case-controlled retrospective analysis. J Chiropr Med 2011;10:179-184.
- Morningstar MW. Four-year follow-up results for a patient receiving chiropractic rehabilitation for adolescent idiopathic scoliosis: a case report. J Pediatr Maternal Family Health 2011;2:54-58.
- Harrison DE, Cailliet R, Harrison DD, Troyanovich SJ, Harrison SO. A review of biomechanics of the central nervous system–Part II: spinal cord strains from postural loads. J Manipulative Physiol Ther. 1999;22:322-332.
