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Jul022010

Postural Alignment & Health Disorders: A Scientific Connection?

DateFriday, July 2, 2010 at 6:43AM

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Deed E. Harrison, DC

President CBP Seminars, Inc.

Vice President CBP Non-Profit, Inc.

Chair PCCRP Guidelines

Editor—AJCC

Editor’s Note: Dr. Deed will be presenting a comprehensive, contemporary review of this topic at the upcoming 32nd CBP Annual Conference on Sept 24-26th, Scottsdale, AZ. See center page and www.idealspine.com for details.

INTRODUCTION
Posture has probably been one of the longest studied aspects of Humans. The correlation of posture and health has driven us to study our posture since at least the time of Hippocrates.1 Since Hippocrates’ time, many have attempted to categorize man into constitutional posture types.1-3

Even in present times, the criteria for normal and abnormal posture continue to be ill defined without clearly defined and agreed upon categories and measures. Before any possible consequences of abnormal posture can be addressed, normal posture must be defined and precise measurement methods developed.

DISCUSSION

  • Ideal Upright Postural Alignment:
Herein, we use the definition of ‘Ideal Posture Alignment’. Ideal Posture is really a matter of simple engineering. The human body is designed such that the centers of mass of the head, ribcage, and pelvis should be perfectly centered and balanced on each other. From the front, the spine is perfectly aligned with gravity. But the spine, when viewed from the side, contains three curves to properly balance the weight of the body and allow free movement. Figure 1 depicts the proposed Ideal Posture Alignment. Note that we will ignore the ideal spinal curvatures that give rise to optimal postural alignment for the purposes of this short presentation.
  • Abnormal Postures as Rotations and Translations:

Now that we have an Idealized Posture Alignment as an origin, we can now look at categories of abnormal postural displacements. In 1974, Panjabi, White, and Brand4 presented a right-handed central orthogonal (Cartesian) coordinate system where local systems (i.e. body joints or segments) may be used to define human body joint and segment static positions or relative motions from the central system. My father (Dr. Donald Harrison) originally (in 1982) implemented this system to define human body posture as rotations and translations of the head, thoracic cage, and pelvis as 12 simple movements in 6 degrees of freedom.5-7

A center of origin to describe the global orientation of the major body masses was defined as right-handed Cartesian coordinate systems describing the origin of the head movements from T2, the thoracic cage from S2, and the pelvis from the mid-talus centered between the feet and in some movements from the femur heads. The single posture component rotations and translations of the head, thorax, and pelvis are shown in Figures 2 and 3.

While there are only 36 possible single movements of the head, thorax, and pelvis shown in Figures 2 and 3, complexity of this system of description is inherent. There can be singles, doubles, triples, quadruples, quintuples, and sextuples of rotations and translations for the head, thoracic cage, or pelvis.
Using just the head, there are 6 degrees of freedom (Rx, Ry, Rz, Tx, Ty, Tz) and three possible choices for direction ( -, 0, +) for a total number of permutations of 36 = 729. In other words, there are 729 unique postural displacement combinations for the head relative to the ribcage; 728 of these would be abnormal postural displacements and 1 would be the ideal alignment position shown in Figure 1.

  • Measurement of Ideal and Abnormal Posture Alignment:

Previous investigations into postural analysis systems have suffered from an incomplete analysis, including use of only one examiner, small sample sizes, and measurement of only one region of the body, or a limited number of degrees of freedom of postural displacements.
Recently, CBP researchers developed a new computerized system (PosturePrint®), to measure head, rib cage, and pelvic postures as rotations and translations in three-dimensions (3-D) in upright stance. In three separate validity studies,8-10 the PosturePrint system was found to be sufficiently accurate in measuring head, thoracic cage, and pelvic postures in five degrees of freedom (vertical translations were not assessed) on inanimate subjects: errors ≤ 3mm and 3°. Further, intra and inter-examiner reliability of the process required for the PosturePrint computer systems’ analysis of upright human posture was evaluated; the PosturePrint measurements were found to have good to excellent examiner reliability.11
The use of the PosturePrint system allows detailed postural measurements to be used clinically to gauge an individual’s response to intervention and/or for research purposes assessing correlations between postural alignment and health disorders. Figure 4 depicts the AP Postural Alignment using the PosturePrint system and the consequent displacements measured: Left pelvic translation, Left thoracic translation, Left thoracic bending, and Right Head translation are the significant findings.

  • Postural Deformity, Pain, Disability & Health:

The cause-effect relationship between postural deformity-abnormality and health disorders has been the subject of numerous investigations and review articles and it has advocates on both sides of the debate. A comprehensive review of this information is behind the scope of the current short presentation. However, recent high quality case control investigations have found interesting and significant differences between condition groups vs. control groups and significant correlations between abnormal posture alignment and a number of health disorders including:

  • Abnormal thoraco-lumbar alignment and back and neck pain in children and adolescents;12,13
  • Hyper-kyphosis-round back and health perceptions and function in adolescents;14,15
  • Hyper-kyphosis and rigid anterior head translation and functional impairments in seniors;16
  • Hyper-kyphosis and early mortality in seniors;17
  • Abnormal cervical spine postures in women with chronic pelvic pain;18
  • Abnormal forward head posture and neck pain, headaches, disability, range of motion, respiratory muscle function, and carpal tunnel syndrome.19-23

At the upcoming 32nd CBP Annual conference in Sept, I will be presenting a comprehensive and contemporary review of this type of information from the scientific literature. However, scientific studies aside, ask yourself or others this question: Which one of the four persons in Figure 4 visually appears to be in good health and which one of the four persons would you say has poor health?
Your eyes (and mind), may in fact be pointing you to answer for the questions regarding the scientific connection between good posture and good health and poor posture and poor health. In the end, how do you wish to age with respect to gravity may be the only question that need be answered.

SUMMARY
This short paper has presented a fundamental yet rigorous model of ideal posture and consequent abnormal posture alignments as components of rotations and translations after Dr. Don Harrison. The use of this posture model has many advantages over previously ill-defined postural ideologies. It is simple to implement into the clinical or research settings and easy to record and communicate between professionals.

References
See AJCC Online at www.idealspine.com for the detailed list of references accompanying this article.

  • Goff CW. J Bone Jt Surg Am 1952;34:115.
  • Beck A, Killus J. Aerospace Medicine 1973;44:1277-1281.
  • During J, et al. Toward standards for posture. Spine 1985;10:83-87.
  • Panjabi MM, White III AA, Brand RA. A note on defining body parts configurations. Journal of Biomechanics 1974;7:385-387.
  • Harrison DD. CBPâ Technique: The Physics of Spinal Correction. National Library of Medicine #WE 725 4318C, 1982-97.
  • Harrison DD. Spinal Biomechanics: A Chiropractic Perspective. National Library of Medicine #WE 725 4318C, 1982-97.
  • Harrison DD, Janik TJ, Harrison GR, Troyanovich SJ, Harrison DE, Harrison SO. Chiropractic Biophysics Technique: A Linear Algebra Approach to Posture in Chiropractic. J Manipulative Physiol Ther 1996;19(8):525-535.
  1. Harrison DE, Janik TJ, Cailliet R, Harrison DD, Normand MC, Perron DL, Ferrantelli JR. Validation of an algorithm to estimate 3-D rotations and translations of the rib cage in upright posture from three 2-D digital images. Eur Spine J 2007; 16(2):213-218.
  2. Janik TJ, Harrison DE, Cailliet R, Harrison DD, Normand MC, Perron DL. Validation of an algorithm to estimate 3-D rotations and translations of the head in upright posture from three 2-D images. J Manipulative Physiol Ther 2007;30(2):124-129.
  3. Harrison DE, Janik TJ, Cailliet R, Harrison DD, Normand MC, Perron DL, Oakley PA. Upright static pelvic posture as rotations and translations in 3-dimensional from three 2-dimensional digital images: validation of a computerized analysis. J Manipulative Physiol Ther 2008 Feb;31(2):137-45.
  4. Normand MC, Descarreaux M, Harrison DD, Harrison DE, Perron DL, Ferrantelli JR, Janik TJ. Three dimensional evaluation of posture in standing with the PosturePrint: an intra- and inter-examiner reliability study. Chiropractic & Osteopathy 2007; Sept. 24th 15:15.
  5. Murphy S, et al. Classroom posture and self-reported back and neck pain in schoolchildren. Appl Ergon 2004;35(2):113-120.
  6. Smith A, et al. Classification of sagittal thoraco-lumbar pelvic alignment of the adolescent spine in standing and its relationship to low back pain. Spine 2008;33:2101-2107.
  7. Korovessis P, et al. Comparative multifactorial analysis of the effects of idiopathic adolescent scoliosis and Scheuermann kyphosis on the self-perceived health status of adolescents treated with brace. Eur Spine J 2007;16:537-546.
  8. Petcharaporn M, et al. The relationship between thoracic hyperkyphosis and the scoliosis research society outcomes instrument. Spine 2007;32:2226-2231.
  9. Kado DM. Narrative Review: Hyperkyphosis in older persons. Ann of Intern Med 2007;147:330-338.
  10. Kado DM, et al. Hyperkyphosis predicts mortality independent of vertebral osteoporosis in older women. Ann Intern Med 2009; 150:681-687.
  11. Mary LLS MontenegroPostural changes in women with chronic pelvic pain: a case control Study. BMC Musculoskeletal Disorders 2009, 10:82.
  12. Fernández C, et al. Forward head posture and neck mobility in chronic tension-type headache: a blinded, controlled study Cephalalgia 2006;26(3):314
  13. Yip CH. The relationship between head posture and severity and disability of patients with neck pain. Man Ther 2008;13:148-154.
  14. Kapreli E, et al. Respiratory dysfunction in chronic neck pain patients. Cephalgia 2009;29:701–710.
  15. De-la-Llave-Rincón A, et al. Increased Forward Head Posture and Restricted Cervical Range of Motion in Patients With Carpal Tunnel Syndrome.J Orthop Sports Phys Ther 2009;39(9):658-664.Lau KT, et al. Relationships between sagittal postures of thoracic and cervical spine, presence of neck pain, neck pain severity and disability. Man Ther 2010; April 28 (E-pub ahead of print).
  16. Lau KT, et al. Relationships between sagittal postures of thoracic and cervical spine, presence of neck pain, neck pain severity and disability. Man Ther 2010; April 28 (E-pub ahead of print).

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