Idiopathic Scoliosis: Is it really that mysterious?

I think everyone can relate to being in a 7th grade gym class or in your pediatrician’s office and having to check for scoliosis. We all know the drill, we bend forward and the tester looks down our spine looking for a curvature or the presence of a rib hump. You might have even had the tester tell you that you had “mild scoliosis.”

For terminology sake, we should understand that while scoliosis means a curvature of the spine and presence of associated rib hump, idiopathic simply means we don’t know what causes scoliosis to occur in these cases.

Note the curve to the right in the med back and to the left in the lower back.

Source: Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)], from Wikimedia Commons

(There are other scoliosis causes such as a brain injury or congenital structural abnormality that constitute different types of scoliosis diagnosis, and may require intervention such as using a scoliosis brace or undergoing scoliosis surgery. )

I hope I can change your mind that there is anything mysterious about idiopathic scoliosis by the end of this article.

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What’s going on here?

“Mild scoliosis” is considered to be benign because to a degree, most humans are predisposed to some lateral curvature of the spine. Related to this observation is the fact that an estimated 90 percent of rib humps are found to occur on the right. In fact, a left rib hump is considered cause for further examination because it represents an abnormal finding, while a slight right rib hump is considered to be a normal finding if below a certain clinical threshold.

Why is “mild scoliosis” a normal finding?

It has been observed by several groups including the Postural Restoration Institute and Karski of the Medical University of Lublin, that humans tend to prefer standing on their right leg. Both groups believe this tendency to stand on the right leg in combination with other findings, tests, and measures, is associated with the development of scoliosis.

Contrapposto stance, illustrating the tendency to stand on the right leg, to “open up” the left side of the body.

Source tetraktys (talk) 20:26, 20 October 2013 (UTC) [CC BY-SA 2.5 (https://creativecommons.org/licenses/by-sa/2.5) or GPL (http://www.gnu.org/licenses/gpl.html)], via Wikimedia Commons

Both groups, have identified common underlying movement dysfunction related to the development of scoliosis, although they describe these phenomena in slightly different terms.

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Karski describes scoliosis causes attributed to the central nervous system to be:

1. Laxity of joints

2. Anterior tilt of pelvis

3. Straight position/contracture of spine

Note the forward inclination of the pelvis, accompanied by excessive lordotic curvature in the lower back and distention of the abdominal cavity. This type of posture is indicative of excessive spine and hip flexor muscle activity.

Note the contracture of the spine in the image on the right. This illustrates the INCORRECT seated posture for an individual that presents with scoliosis. The “physiological” or relaxed posture on the left is the CORRECT seated posture.

Other findings include:

1. Contracture of hip flexors

2. Asymmetry in ability to adduct (move towards midline) each hip

3. Stand at ease test (looking for tendency to stand on the right leg)

4. Asymmetrical standing internal rotation of right and left hips (left hip lacking 30 degrees of internal rotation)

Note the inability to shift the left pelvis over the left leg, lacking ~ 30 degrees of internal rotation on the left side. This reflects a forward orientation of the left pelvis and furthers the tendency to stand on the right leg.

Postural Restoration addresses scoliosis by inhibiting the overactivity of chains of muscles that are associated with altered breathing patterns and postural asymmetry. In the PRI model, the asymmetry seen in scoliosis is attributed to:

1. Tendency to stand on the right leg, due to the asymmetry of the chest and abdominal cavities, and diaphragm favoring stability/force production on the right

2. Acquired positional torsion as a result of altered breathing patterns and associated neuromuscular recruitment

3. Orientation of the spine to the right causes a relative anterior tilt of the pelvis on the left side, which ultimately promotes overuse of the spinal extensors and lengthening/weakening of the lateral abdominals

PRI also has many findings in common with Karski, including:

1. Asymmetrical adduction (move towards midline) of the hip, described as the adduction drop test (ADT)

Ron Hruska (director of Postural Restoration Institute) discusses the Adduction Drop Test and the Abduction Lift Test.

In terms of treatment, the PRI group states interventions include:

1. Improving internal rotation of the left hip, specifically the ability to move the left hemipelvis over the left femur

2. Restoring normal breathing patterns, including filling the right chest wall with air, and training the left diaphragm to work with the left abdominals

3. Recruiting muscles such as the hamstrings to reposition the anterior tilt of the pelvis

Ron Hruska instructs a patient on how to perform the 90-90 Hip Lift with Balloon exercise technique.

In this exercise, the hamstrings are utilized to reposition the pelvis, as the balloon facilitates proper recruitment of abdominals, chest wall muscles and repositions the rib cage so that the diaphragm is in an optimal position to normalize air flow (to the right chest wall).

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Two independent groups are looking at scoliosis in much the same way. When we examine the fact that an estimated 90% of curvature occur to the right, it starts to become clear that there’s nothing idiopathic about this kind of scoliosis at all.

Scoliosis likely represents a universal human phenomenon that is occurring to some degree, whether measurable or not, in almost every human being.

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So why do some develop symptoms from scoliosis while others do not?

Interestingly enough, it is those with joint laxity that Karski and Jacek identify as having an increased risk for the development of scoliosis, as well as those who exhibit extension dominance at a young age. This makes sense if we consider that there is an underlying pattern, and that those who have less inherent resistance to the pattern, tend to suffer more extreme consequences of the pattern.

Another reason might be that those who have more joint laxity have decreased ability to sense where their joints are in space, experience decreased ability to stabilize their joints, and rely on end-range loading of passive structures such as ligaments and joint capsules in order to stabilize themselves.

For example, if someone adopts a swayback posture, they tend to lean forward into their hips, and then sway back in their thoracic spine, which exaggerates curvature of the lower spine and anterior tilting of the pelvis. This type of position disadvantages the abdominals from providing the necessary support to work with the diaphragm to promote optimal breathing and exaggerates any tendency to overuse extension-dominant muscles. These factors likely exacerbate neuromuscular patterns that contribute to the development of scoliosis.

Note how the individual leans into their hips and then “sways back” with their ribcage and mid back. The individual demonstrates increased lordotic curvature in the lower back, kyphotic curvature in the mid back, scapular winging, and abdominal distention.

Source: Non-structural misalignments of body posture in the sagittal plane - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Sway-back-posture-in-a-11-year-old-boy-a-Habitual-standing-lateral-view-b_fig7_323558106 [accessed 11 Dec, 2018]

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If two groups aren’t enough, let’s consider a third?

In Shirley Sahrmann’s book, Diagnosis and Treatment of Movement Impairment Syndromes, she categorizes movement pattern dysfunction in order of most frequently observed. While not discussing the patterns in terms of scoliosis, further inspection will demonstrate how these findings correlate with those described above.

In the section on the lumbar spine, she lists the two most commonly observed movement dysfunctions as:

1. Extension with rotation

2. Extension without rotation

If we cross-reference this with the PRI model, extension with rotation fits nicely with the left anterior interior chain dysfunction that is characterized by weakening of the left abdominal wall/diaphragm, and overactivity of the left back extensors. If we look at rotation without extension, this fits nicely with the posterior exterior chain dysfunction which PRI describes as a two-sides extension dominant pattern that is superimposed on top of a unilateral extension pattern. In this case, an extension strategy on both sides is an adaptation to trying to promote symmetry in a system that is already in extension due to the baseline tendencies described above.

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So how do we treat this?

1. Kasarski and Jacek recommend implementing scoliosis exercises that emphasize flexion with rotation between the ages of 3 and 4.

2. PRI recommends inhibiting extensor chain muscles (especially on the left) by facilitating abdominals, respiratory function, and flexor-chain muscles. The end result, is a reduction in the torsion into extension and rotation and a movement towards flexion and rotation in the opposite direction of the torsion.

3. Shirley Sahrmann recommends using abdominals to control extension and rotation, and avoiding activities that further the pattern.

To summarize, at some level each group is saying:

1. We need to FLEX!!! (or at least control extension)

2. We need to ROTATE in the opposite direction (or at least control rotation in the wrong direction)

Flexing and rotating…. WTF?!

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This brings us to an interesting place.

If you’ve ever talked to a physical therapist, orthopedic physician, or chiropractor, you might have heard that flexing and rotating is exactly what you want to avoid. After all, isn’t bending and rotating the number one cause of disc-related injuries?

I dug up a few studies that actually showed an association between scoliosis and herniated disc pathology. In fact, in one study they demonstrated that surgical treatment of the herniated disc reduced scoliosis in a group of adolescents.

This is where it gets tricky. In one of the reviewed studies, patients were said to lack the ability to flex, with the implication being that an inability to flex was due to the pain associated with a herniated disc. However, in the case of children having a spine contracture as described above, it is neurological tone and not the presence of a herniated disc that is responsible for this functional limitation, so we should proceed with skepticism when interpreting the findings of these (out of date) studies.

In fact, recent evidence suggests that the majority of people have herniated discs which are asymptomatic, and often symptoms associated with back pain in the presence of a herniated disc are due to other pain generators than the disc (muscle strain, joint degeneration, impingement of nerve roots due to narrowing of the spine).

So are these individuals flexing and rotating too much, or extending and rotating too much?

Looks can be deceiving.

One interesting finding was that young patients who underwent surgery for disc herniations had a decreased normal curvature (lordosis) in their lumbar spine. This might seem surprising given the fact that the back extensor muscle group is typically thought to increase lordosis, but when looking at studies which examine factors associated with decreased lordosis, it is observed that most patients with decreased lordosis have a history of back muscle spasm. It is hypothesized that one cause of the flattening of the natural curve of the lower back is degenerative changes that occur from sustained compressive loading secondary to muscle spasm.

Note the lack of curvature in the spine, often attributed to excessive spinal muscle activity.

Source: By © Nevit Dilmen, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17759550

If it is the case that those with scoliosis often have decreased curves in their lower back due to muscle spasm, it should not surprise us given the findings we discussed earlier that young children with scoliosis are observed to have contractures of the spinal muscles. In this case, counterintuitive as it might seem, using muscles associated with flexion and rotation away from the torsion may provide an inhibitory effect to the spinal muscles that are overworked, thus limiting further associated flattening of the lower back.

This is an example of how looking at the system as purely mechanical, without understanding the neurological basis of malpositioning, can lead us to make the exact wrong judgement in terms of our rehabilitation program. Karski and Jacek highlight that a common pitfall in scoliosis exercises include emphasis on back extension exercises. In fact, I’d contend that back extension exercises likely aren’t beneficial for any human being, especially one who has asymmetry of the hips, laxity in their joints, or excessive extension patterning.

Example of incorrect exercise. This is likely to exaggerate tendency toward torque/asymmetry .

Source: Karski doi:10.4172/2165-7025.1000147

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So what are the potential implications for training?

Things we likely need to focus on:

1. Breathing - all the way out, and equally on both sides

2. Proper positioning- learning how to balance our body in three planes

3. Learn to stand on our left leg with ease- Improve internal rotation of the pelvis on the left leg

4. Train muscles to control the tendency to extend and rotate our spine, rib cage, and pelvis

   1. Hamstrings (especially left)

   2. Glutes

   3. Abdominals (especially left)

   4. Adductors (especially left)

5. Preserve the ability to relax spinal muscles- especially during bending tasks, particular attention to the thoracic spine at the level of the diaphragm

   1. Deep squats

   2. Reaching activities

6. Sit physiologically (relax)

   1. Avoid sitting straight up

7. Sleep in the fetal position

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For a further look at a series of exercises I have been using, which are inspired in part by PRI methodology and in part by my own experience with asymmetry, check out my latest video:

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Sources:

1. Susan Henning, Lisa C. Mangino and Jean Massé (September 27th 2017). Postural Restoration: A Tri-Planar Asymmetrical Framework for Understanding, Assessing, and Treating Scoliosis and Other Spinal Dysfunctions, Innovations in Spinal Deformities and Postural Disorders, Josette Bettany-Saltikov and Sanja Schreiber, IntechOpen, DOI: 10.5772/intechopen.69037. Available from: https://www.intechopen.com/books/innovations-in-spinal-deformities-and-postural-disorders/postural-restoration-a-tri-planar-asymmetrical-framework-for-understanding-assessing-and-treating-sc

2. Tomasz Karski J. So-Called Idiopathic Scoliosis: Diagnostic Tests: Examples of Children Incorrect Treated: New Therapy by Stretching Exercises and Results. Journal of Novel Physiotherapies. 2013;3(03). doi:10.4172/2165-7025.1000147

3. Tomasz Karski J. So-Called Idiopathic Scoliosis: Diagnostic Tests: Examples of Children Incorrect Treated: New Therapy by Stretching Exercises and Results. Journal of Novel Physiotherapies. 2013;3(03). doi:10.4172/2165-7025.1000147

4. Pinto F, Poetscher A, Quinhones F, Pena M, Taricco M. Lumbar disc herniation associated with scoliosis in a 15-year-old girl: case report. Arq Neuropsiquiatr. 2002;60(2A):295-298. doi:10.1590/s0004-282x2002000200022

5. Chun SW, Lim CY, Kim K, Hwang J, Chung SG. The relationships between low back pain and lumbar lordosis: a systematic review and meta-analysis. Spine J. 2017 Aug;17(8):1180–1191. PubMed #28476690.

6. Sparrey C, Bailey J, Safaee M et al. Etiology of lumbar lordosis and its pathophysiology: a review of the evolution of lumbar lordosis, and the mechanics and biology of lumbar degeneration. Neurosurg Focus. 2014:E1. doi:10.3171/2014.1.focus13551

7. Epstein AJ, Epstein NE, Marc J. Lumbar intervertebral disk herniation in teenage children, recognition and management of associated anomalies. Spine 1984;9:427-432.

8. Borgesen SE, Vang PS. Herniation of the lumbar intervertebral disc in children and adolescent. Acta Orthop Scand 1974;45:540-549.

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