I thought this might be of general interest to some folks. It offers a fairly diverse display and analysis of a variety of studies performed. Interesting reading at the least.
to be continued...
Scoliosis and Proprioception
Robert Schleip
Published in Rolf Lines, Vol. 28, No.4 (Fall 2000)
Most types of scoliosis are classified as ‘idiopathic scoliosis’ which means that the reasons for this type of rotational deformity of the spine are yet unknown. Nevertheless there are all kinds of assumptions, beliefs and anectdotal reports available in the alternative health community concerning the main causes and driving factors. For example the following factors have been suggested as causes : traumatic events (if birth trauma, then scoliosis is believed to start at the cranial end, if sexual trauma usually at the caudal end), visceral tensions (uncomplete embryological rotational movement of organs); psychological problems (not facing the world, making yourself smaller), unilateral psoas shortening, nutrition, the Corriolis force (which makes hurricans and bath tap water to spiral in a counter-clockwise motion in the Northern hemisphere) and so on. Yet when applying usual scientific research standards, most of these claims have not been able to be substantiated, despite the fact that every year an impressive amount of money and research projects is devoted to improve our understanding of the causes of this dysfunction.
In preparation of my recent talk on ‘Working with Scoliosis’ at the Annual Rolfing Conference 2000, I did a MEDLINE search of published scientific research papers on this subject. While most of the papers are still on surgical and measuring techniques, there have also been a few hundred published studies in the last decade which concern the etiology and causative factors of this deformity. I will try to summarize some of the themes and findings here:
• Among identical twins the concordance rate for idiopathic scoliosis is about twice as high as among non-identical twins. This is seen as strong evidence for a genetic predisposition; although environmental factors seem to be involved too.
• Chicken whose pineal gland is cut away, develop scoliosis with very similar features to that of an idiopathic scoliosis in humans. Since the pineal gland produces only one hormone, melatonin, it had been suggested that melatonin deficiency could be a primary factor for scoliosis in humans (as well as in chicken). In January of this year a study was published that showed in fact a lower melatonin serum level in scoliotic patients than in a matched control group. Yet just a few months later a more careful study was published, which had been measuring the serum level throughout the whole day; and this study did not show any signficant differences in the melatonin level of scoliotic patients compared with others. Also more recent studies with chicken showed that the induced scoliosis after pinealectomy has probably more to do with a secondary lack of serotonin (which has been known to influence general muscle tonus).
• Attempts to link idiopathic scoliosis with changes in genetic collagen morphology, or with zinc or potassium levels in the body have failed.
• Also no correlation could be found with the position or functioning of visceral organs. Except that in high-degree scoliosis the position of the aorta is changed. Yet this has been shown to be a secondary effect of the scoliosis, not related to a primary causative factor.
• Attempts to decrease the degree of scoliosis by cutting the psoas on the suspected ‘short side’ have failed. . This is also congruent to my own experiences in testing the myofascial length of the iliopsoas in the ‘Thomas Test’ manouver. My scoliotic clients seem to have ‘on average’ a similar myofascial length of the iliopsoas as other people.
• Histochemical analysis of the paravertebral muscles showed no myopathic changes. Flexiblity studies of the lumbar spine, shoulder and hip joints showed no significant changes to a control group. This findng points to idiopathic scoliosis being an organic rather than a systemic disease.
• A computer aided biomechanical three-dimensional osseo-ligamentous model of the human thorax was constructed to explore how asymmetric growth of the thorax might initiate spinal lateral curvature and axial rotation as seen in idiopathic scoliosis. In fact their model showed that slightly larger ribs on one side could result both in a sidebending convexity towards that side plus in an axial rotation of the spine similar to that observed clinically. "The model supports the idea that growth asymmetry could initiate a small scoliosis during adolescence".
• An anatomical study of muscle biomechanics found that the "spatial displacement of vertebrae in idiopathic scoliosis is not explicable by forces created by the muscles which act upon the spine only (intrinsic muscles). The trapezius and latissimus muscles are attached to the spinous processes and the upper limb". "The peculiarity of the vertebral anatomy, together with the direction of pull of these muscles, permits an explanation of the biomechanics of the development of 'idiopathic' scoliosis"
• "A 10-fold higher incidence of scoliosis was found in rhythmic gymnastic trainees (12%) than in their normal coevals (1.1%). Delay in menarche and generalized joint laxity are common in rhythmic gymnastic trainees". The study observed "a significant physical loading with the persistently repeated asymmetric stress on the growing spine" in these young gymnasts. A"dangerous triad" is attributed for the etiology of this type of idiopathic scoliosis: "generalized joint laxity, delayed maturity, and asymmetric spinal loading".
• In general the morphology of scoliotic clients has less mesomorphic features. This seems to be also a predictive factor: if the mesomorphic values are low on the SHELDON typology, the scoliosis has a high probability to increase with age.
• The multifidus fibers tend to be more fast twitch than normal on the concave side of the apex (most likely as a result and not cause of the sidebending). Myofascial release work on the (shortened) concave side tissues yielded significant improvements in one study.
• Trunk rotation against resistance is usually weaker in one direction. A systematic strength training using a MedX Torso Rotation exercise machine, seemed to improve the degree of scoliosis in a recent study.
• MRI studies have shown significant proportion of abnormalities in the brain stem area (as well as in the spinal cord) among idiopathic scoliosis clients when compared with other types of spinal assymmetries or normal people.
• A significant correlation with otolith vestibular dysfunction could be shown. An interesting newer finding (which needs to be confirmed by others) is that people with hearing problems seem to be ‘immunized’ against idiopathic scoliosis; i.e. idiopathic scoliosis seems to be much more rare among them than in normal people. Which is seen as another indication for a strong neural factor in the etiology of scoliosis.
• Previous attempts to show a correlation between handedness and the direction of the primary curve had failed. Yet a newer study looked at the direction of convexity of the low thoracic spine regardless of the primary curvature. Their result: "The correlation between scoliosis configuration and handedness was statistically significant. This is in contrast to the findings of previous studies, which have considered convexity only, without reference to the configuration of the whole spine. The implication of this finding is that scoliosis is associated with cortical functions".
This seems to be the general trend in scoliosis research: compared with previous years most of the newer research apparently explores the central nervous system as a primary causative factor. The study by Maguire et al on ‘Abnormal Central Processing’ (see article from Jerry Larson about it in this issue of ROLF LINES) is a typical example of it. It fits very nicely to another study, which I found even more intriguing, and which I will therefore choose for a more detailed description here. The study is called ‘Proprioceptive Accuracy in Idiopathic Scoliosis’ and was done by W.Keesen and others in the Netherlands. With the pulisher’s permission, let me quote from the original text and also add some commentaries from my side.
The article starts with: "Defects in proprioceptive postural control have been linked to the etiology of idiopathic scoliosis". Actually this has been found in several studies already since the early 80ies: that postural control – e.g.. walking on a high beam – tends to be less accurate in these people. Also the amplitude of their ‘postural sway’ – i.e. the balancing movements of the body in standing – has been found to be slightly larger than normal. Yet it was unclear whether that is the result or the cause of the spinal deformation.
The article goes on "In particular a rearrangement of the internal representation of the body has been proposed in these cases." Now this sentence caught my personal interest, as I am quite fascinated in the correlations of outer body changes with specific dysfunctions in cortical body representation. In other words there is some evidence that the diminished postural control in these clients does not come from a less accurate motor execution but from a perceptual weakness based on an inaccurate ‘body image’ in their brain. Rolf Movement Practitioners, Feldenkrais Teachers, and other somatic practitioners involved with the internal body organization, this is your field!
Robert Schleip
Published in Rolf Lines, Vol. 28, No.4 (Fall 2000)
Most types of scoliosis are classified as ‘idiopathic scoliosis’ which means that the reasons for this type of rotational deformity of the spine are yet unknown. Nevertheless there are all kinds of assumptions, beliefs and anectdotal reports available in the alternative health community concerning the main causes and driving factors. For example the following factors have been suggested as causes : traumatic events (if birth trauma, then scoliosis is believed to start at the cranial end, if sexual trauma usually at the caudal end), visceral tensions (uncomplete embryological rotational movement of organs); psychological problems (not facing the world, making yourself smaller), unilateral psoas shortening, nutrition, the Corriolis force (which makes hurricans and bath tap water to spiral in a counter-clockwise motion in the Northern hemisphere) and so on. Yet when applying usual scientific research standards, most of these claims have not been able to be substantiated, despite the fact that every year an impressive amount of money and research projects is devoted to improve our understanding of the causes of this dysfunction.
In preparation of my recent talk on ‘Working with Scoliosis’ at the Annual Rolfing Conference 2000, I did a MEDLINE search of published scientific research papers on this subject. While most of the papers are still on surgical and measuring techniques, there have also been a few hundred published studies in the last decade which concern the etiology and causative factors of this deformity. I will try to summarize some of the themes and findings here:
• Among identical twins the concordance rate for idiopathic scoliosis is about twice as high as among non-identical twins. This is seen as strong evidence for a genetic predisposition; although environmental factors seem to be involved too.
• Chicken whose pineal gland is cut away, develop scoliosis with very similar features to that of an idiopathic scoliosis in humans. Since the pineal gland produces only one hormone, melatonin, it had been suggested that melatonin deficiency could be a primary factor for scoliosis in humans (as well as in chicken). In January of this year a study was published that showed in fact a lower melatonin serum level in scoliotic patients than in a matched control group. Yet just a few months later a more careful study was published, which had been measuring the serum level throughout the whole day; and this study did not show any signficant differences in the melatonin level of scoliotic patients compared with others. Also more recent studies with chicken showed that the induced scoliosis after pinealectomy has probably more to do with a secondary lack of serotonin (which has been known to influence general muscle tonus).
• Attempts to link idiopathic scoliosis with changes in genetic collagen morphology, or with zinc or potassium levels in the body have failed.
• Also no correlation could be found with the position or functioning of visceral organs. Except that in high-degree scoliosis the position of the aorta is changed. Yet this has been shown to be a secondary effect of the scoliosis, not related to a primary causative factor.
• Attempts to decrease the degree of scoliosis by cutting the psoas on the suspected ‘short side’ have failed. . This is also congruent to my own experiences in testing the myofascial length of the iliopsoas in the ‘Thomas Test’ manouver. My scoliotic clients seem to have ‘on average’ a similar myofascial length of the iliopsoas as other people.
• Histochemical analysis of the paravertebral muscles showed no myopathic changes. Flexiblity studies of the lumbar spine, shoulder and hip joints showed no significant changes to a control group. This findng points to idiopathic scoliosis being an organic rather than a systemic disease.
• A computer aided biomechanical three-dimensional osseo-ligamentous model of the human thorax was constructed to explore how asymmetric growth of the thorax might initiate spinal lateral curvature and axial rotation as seen in idiopathic scoliosis. In fact their model showed that slightly larger ribs on one side could result both in a sidebending convexity towards that side plus in an axial rotation of the spine similar to that observed clinically. "The model supports the idea that growth asymmetry could initiate a small scoliosis during adolescence".
• An anatomical study of muscle biomechanics found that the "spatial displacement of vertebrae in idiopathic scoliosis is not explicable by forces created by the muscles which act upon the spine only (intrinsic muscles). The trapezius and latissimus muscles are attached to the spinous processes and the upper limb". "The peculiarity of the vertebral anatomy, together with the direction of pull of these muscles, permits an explanation of the biomechanics of the development of 'idiopathic' scoliosis"
• "A 10-fold higher incidence of scoliosis was found in rhythmic gymnastic trainees (12%) than in their normal coevals (1.1%). Delay in menarche and generalized joint laxity are common in rhythmic gymnastic trainees". The study observed "a significant physical loading with the persistently repeated asymmetric stress on the growing spine" in these young gymnasts. A"dangerous triad" is attributed for the etiology of this type of idiopathic scoliosis: "generalized joint laxity, delayed maturity, and asymmetric spinal loading".
• In general the morphology of scoliotic clients has less mesomorphic features. This seems to be also a predictive factor: if the mesomorphic values are low on the SHELDON typology, the scoliosis has a high probability to increase with age.
• The multifidus fibers tend to be more fast twitch than normal on the concave side of the apex (most likely as a result and not cause of the sidebending). Myofascial release work on the (shortened) concave side tissues yielded significant improvements in one study.
• Trunk rotation against resistance is usually weaker in one direction. A systematic strength training using a MedX Torso Rotation exercise machine, seemed to improve the degree of scoliosis in a recent study.
• MRI studies have shown significant proportion of abnormalities in the brain stem area (as well as in the spinal cord) among idiopathic scoliosis clients when compared with other types of spinal assymmetries or normal people.
• A significant correlation with otolith vestibular dysfunction could be shown. An interesting newer finding (which needs to be confirmed by others) is that people with hearing problems seem to be ‘immunized’ against idiopathic scoliosis; i.e. idiopathic scoliosis seems to be much more rare among them than in normal people. Which is seen as another indication for a strong neural factor in the etiology of scoliosis.
• Previous attempts to show a correlation between handedness and the direction of the primary curve had failed. Yet a newer study looked at the direction of convexity of the low thoracic spine regardless of the primary curvature. Their result: "The correlation between scoliosis configuration and handedness was statistically significant. This is in contrast to the findings of previous studies, which have considered convexity only, without reference to the configuration of the whole spine. The implication of this finding is that scoliosis is associated with cortical functions".
This seems to be the general trend in scoliosis research: compared with previous years most of the newer research apparently explores the central nervous system as a primary causative factor. The study by Maguire et al on ‘Abnormal Central Processing’ (see article from Jerry Larson about it in this issue of ROLF LINES) is a typical example of it. It fits very nicely to another study, which I found even more intriguing, and which I will therefore choose for a more detailed description here. The study is called ‘Proprioceptive Accuracy in Idiopathic Scoliosis’ and was done by W.Keesen and others in the Netherlands. With the pulisher’s permission, let me quote from the original text and also add some commentaries from my side.
The article starts with: "Defects in proprioceptive postural control have been linked to the etiology of idiopathic scoliosis". Actually this has been found in several studies already since the early 80ies: that postural control – e.g.. walking on a high beam – tends to be less accurate in these people. Also the amplitude of their ‘postural sway’ – i.e. the balancing movements of the body in standing – has been found to be slightly larger than normal. Yet it was unclear whether that is the result or the cause of the spinal deformation.
The article goes on "In particular a rearrangement of the internal representation of the body has been proposed in these cases." Now this sentence caught my personal interest, as I am quite fascinated in the correlations of outer body changes with specific dysfunctions in cortical body representation. In other words there is some evidence that the diminished postural control in these clients does not come from a less accurate motor execution but from a perceptual weakness based on an inaccurate ‘body image’ in their brain. Rolf Movement Practitioners, Feldenkrais Teachers, and other somatic practitioners involved with the internal body organization, this is your field!
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