Chiropractic Care

Clinical Biomechanics: General Spinal Biomechanics

By Frank M. Painter|January 3, 2013|Chiropractic Care, Clinical Decision-making, Education|

Clinical Biomechanics: General Spinal Biomechanics

We would all like to thank Dr. Richard C. Schafer, DC, PhD, FICC for his lifetime commitment to the profession. In the future we will continue to add materials from RC’s copyrighted books for your use.

This is Chapter 6 from RC’s best-selling book:

“Clinical Biomechanics:
Musculoskeletal Actions and Reactions”

Second Edition ~ Wiliams & Wilkins

These materials are provided as a service to our profession. There is no charge for individuals to copy and file these materials. However, they cannot be sold or used in any group or commercial venture without written permission from ACAPress.

Chapter 6: General Spinal Biomechanics

This chapter discusses the vertebral column as a whole and serves as a foundation for the following three chapters that consider the regional aspects of the spine and pelvis. Emphasis here is on gross structure, function, spinal kinematics, and other general biomechanical implications.

Background

The vertebral column is a mechanical marvel in that it must afford both rigidity and flexibility.

The Spine as a Whole

The segmental design of the vetebral column allows adequate motion among the head, trunk, and pelvis; affords protection of the spinal cord; transfers weight forces and bending moments of the upper body to the pelvis; offers a shockabsorbing apparatus; and serves as a pivot for the head. Without stabilization from the spine, the head and upper limbs could not move evenly, smoothly, or support the loads imposed upon them (Fig. 6.1).

Essentially because of its various adult curvatures, the bony spine is anatomically divided into the seven cervical vertebrae, the twelve thoracic vertebrae, the five lumbar vertebrae, and the ossified five sacral and four coccygeal segments. From C1 to S1, the articulating parts of these vertebrae are the vertebral bodies, which are separated by intervertebral discs (IVD’s), and the posterior facet joints. The IVD’s tend to be static weight-bearing joints, while the facets function as dynamic sliding and gliding joints.

WEIGHT DISTRIBUTION

The flexible vertebral column is balanced upon its base, the sacrum. In the erect position, weight is transferred across the sacroiliac joints to the ilia, then to the hips, and then to the lower extremities. In the sitting position, weight is transferred from the sacroiliac joints to the ilia, and then to the ischial tuberosities.

SPINAL LENGTH

About 75% of spinal length is contributed by the vertebral bodies, while 25% of its length is composed of disc material. The contribution by the discs, however, is not spread evenly throughout the spine. About 20% of cervical and thoracic length is from disc height, while approximately 30% of lumbar length is from disc height. In all regions, the contribution by the discs diminishes with age.

Development of the Spine

In brief, development occurs in three stages: mesenchymal, chondrification, and ossification.

MESENCHYMAL AND CHONDRIFICATION ORIGINS

Just prior to the 4th week of embryonic development, a vertebral segment begins to develop as paired condensations of mesenchyme (somites) around the longitudinal notochord and dorsal neural tube. One or usually two chondrification centers appear (6 weeks) in the centrum and begin to form a cartilaginous model surrounded by anterior and posterior longitudinal ligaments which are complete by 7-8 weeks. Chondrification centers also form in the neural arches and costal processes. A thick ring of nonchrondrous cells establishes the model IVD around the longitudinal string of beaded notochordal segments (Fig. 6.2). (more…)

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Choice: It Really Does Matter!

By Frank M. Painter|December 19, 2012|Chiropractic Care, Spinal Manipulation, Unnecessary Surgery|

Choice: It Really Does Matter!

The Chiro.Org Blog

SOURCE: Spine (Phila Pa 1976). 2012 Dec 12. [Epub ahead of print]

Keeney, Benjamin J. PhD; Fulton-Kehoe, Deborah PhD, MPH; Turner, Judith A. PhD; Wickizer, Thomas M. PhD; Chan, Kwun Chuen Gary PhD; Franklin, Gary M. MD, MPH

Department of Orthopaedics, Geisel School of Medicine at Dartmouth College, Lebanon, NH 03756, USA. Benjamin.J.Keeney@Dartmouth.edu

This review, by scientists at the Department of Orthopaedics at the Geisel School of Medicine, clearly suggests that the first doctor you choose to see will have a profound effect on whether you end up having spinal surgery.

Just look at these stats:

42.7% of workers who first saw a surgeon ended in surgery, as opposed to only

1.5% of those who (first) saw a chiropractor.

The authors conclude: “There was a very strong association between surgery and first provider seen for the injury, even after adjustment for other important variables.”

The Abstract:

Study Design Prospective population-based cohort study

Objective To identify early predictors of lumbar spine surgery within 3 years after occupational back injury (more…)

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New Oregon LBP Guidelines: Try Chiropractic First

By Frank M. Painter|December 17, 2012|Chiropractic Care, Guidelines, Low Back Pain|

New Oregon LBP Guidelines: Try Chiropractic First

The Chiro.Org Blog

SOURCE: Dynamic Chiropractic

By Vern Saboe, DC, DACAN, DABFP, FACO

Lobbyist, Oregon Chiropractic Association

The new State of Oregon Evidence-Based Clinical Guidelines for the Evaluation and Management of Low Back Pain recommends spinal manipulation as the only nonpharmacological treatment for acute lower back pain. The guidelines, which have been adopted by the Oregon Health Authority, are a collaborative effort between the Center for Evidence-Based Practice, Oregon Corporation for Health Care Quality, Oregon Health and Sciences University’s Center for Evidence-based Policy, and the new Oregon Health Evidence Review Commission.

The Oregon Chiropractic Association (OCA) repeatedly gave written and oral testimony that the original draft guidelines placed too much emphasis on drugs and surgery. A close review of the original algorithm, “Management of Low Back Pain (LBP) (Image 2), relative to “#23 Signs or symptoms of radiculopathy or spinal stenosis,” reveals this. For example, if subsequent special imaging (MRI) revealed concordant nerve root impingement or spinal stenosis (#25), the original draft algorithm led the clinician into a surgical or other invasive procedure “dead end,” meaning there was no contingency for conservative chiropractic treatment (#26).

Image 2 (above)
—> Is Now Discontinued

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Efficacy of Chiropractic Manual Therapy on Infant Colic: A Pragmatic Single-Blind, Randomized Controlled Trial

By Frank M. Painter|November 25, 2012|Chiropractic Care, Colic, Pediatrics|

Efficacy of Chiropractic Manual Therapy on Infant Colic: A Pragmatic Single-Blind, Randomized Controlled Trial

The Chiro.Org Blog

SOURCE: J Manipulative Physiol Ther. 2012 (Oct); 35 (8): 600–607

Joyce E. Miller, BS, DC, David Newell, PhD, and
Jennifer E. Bolton, PhD

Associate Professor,
Anglo-European College of Chiropractic,
Bournemouth, UK.
jmiller@aecc.ac.uk.

Dr. Miller wrote a follow-up to this study, a cost comparison of the medical and chiropractic care provided in her earlier RTC study, titled:

Costs of Routine Care For Infant Colic in the UK and Costs of Chiropractic Manual Therapy as a Management Strategy Alongside a RCT For This Condition
J Clinical Chiropractic Peds 2013 (Jun); 14 (1): 1063–1069

This RTC cast new and significant insights into previous colic trials:

Chiropractic care lowered overall costs more than 400% compared with medical management
The current study revealed that excessively crying infants were 5 times less likely to cry significantly, if they were treated with chiropractic manual therapy, and that chiropractic care reduced their crying times by about 50%, compared with those infants provided solely medical management.

OBJECTIVE: The purpose of this study was to determine the efficacy of chiropractic manual therapy for infants with unexplained crying behavior and if there was any effect of parental reporting bias.

METHODS: Infants with unexplained persistent crying (infant colic) were recruited between October 2007 and November 2009 at a chiropractic teaching clinic in the United Kingdom. Infants younger than 8 weeks were randomized to 1 of 3 groups: (i) infant treated, parent aware; (ii) infant treated, parent unaware; and (iii) infant not treated, parent unaware. The primary outcome was a daily crying diary completed by parents over a period of 10 days. Treatments were pragmatic, individualized to examination findings, and consisted of chiropractic manual therapy of the spine. Analysis of covariance was used to investigate differences between groups.

RESULTS: One hundred four patients were randomized. In parents blinded to treatment allocation, using 2 or less hours of crying per day to determine a clinically significant improvement in crying time, the increased odds of improvement in treated infants compared with those not receiving treatment were statistically significant at day 8 (adjusted odds ratio [OR], 8.1; 95% confidence interval [CI], 1.4-45.0) and at day 10 (adjusted OR, 11.8; 95% CI, 2.1-68.3). The number needed to treat was 3. In contrast, the odds of improvement in treated infants were not significantly different in blinded compared with nonblinded parents (adjusted ORs, 0.7 [95% CI, 0.2-2.0] and 0.5 [95% CI, 0.1-1.6] at days 8 and 10, respectively).

CONCLUSIONS: In this study, chiropractic manual therapy improved crying behavior in infants with colic. The findings showed that knowledge of treatment by the parent did not appear to contribute to the observed treatment effects in this study. Thus, it is unlikely that observed treatment effect is due to bias on the part of the reporting parent.

Introduction

Excessive infant crying in otherwise healthy infants, traditionally called infant colic, continues to be an enigmatic condition with no known cause and no known cure. [1-3] Afflicting between 10% to 30% of all infants and consuming significant health care resources, [2] infant colic is a problem for parents and clinicians, both of whom try a wide range of therapies with often disappointing results.

You may review the earlier Colic studies at:

The Infantile Colic and Chiropractic Page

and you may also enjoy our

Chiropractic Pediatrics Page

Despite decades of research, a clear pathogenesis has not been elucidated. Notwithstanding, what is clear is that underlying disease is rare in the excessively crying baby [4] and that half of those affected recover by 6 months of age, [5] with a small proportion at risk of injury [6] or long-term developmental problems. [7-9] In an effort to help their child with what appears to be a painful condition, some parents choose complementary and alternative medicine (CAM), including chiropractic manual therapy. [9-12] To date, several randomized trials have been reported, [13-19] and although these trials demonstrate some reduction in crying, weaknesses in study methodologies have compromised their contribution to the evidence base. [20-23]

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The Mechanics of Neck Manipulation With Special Consideration of the Vertebral Artery

By Frank M. Painter|November 22, 2012|Chiropractic Care, Stroke|

The Mechanics of Neck Manipulation With Special Consideration of the Vertebral Artery

The Chiro.Org Blog

SOURCE: J Can Chiropr Assoc. 2002 (Sep); 46 (3): 134–136

Dr. W Herzog, BSc, PhD and Dr. B Symons, DC

University of Calgary,
2500 University Drive N.W., Calgary,
Alberta, Canada T2N 1N4.
walter@kin.ucalgary.ca

In recent weeks, we have learnt that chiropractors may have to carefully review the application of high-speed, low-amplitude spinal manipulative treatments to the neck. The concern is the possible risk associated with neck manipulation. Specifically, vertebral artery dissection, or ther mechanical injury, are an acknowledged, albeit a very low, risk.

The vast amount of research on vertebrobasilar injury in the past has been focused on blood flow through the vertebral artery during diagnostic, and before and after manipulative treatment. There was (is) concern that vertebral artery occlusion may occur during neck manipulation, and that a lack of blood supply to the brain may lead to a series of complications. This line of argument has always struck us as weak, because a high-speed, low-amplitude thrust to the cervical spine lasts typically less than 150 ms, and the brain has sufficient oxygen to survive such a small amount of (possible) loss of blood flow from one of its many supply arteries.

Another way of attempting to gain insight into the possible risk of neck manipulation and vertebrobasilar accidents is a statistical (epidemiological) approach. The basic question that people would like to answer is: are people who receive neck manipulative treatments at a greater risk of vertebrobasilar accidents than people who do not receive such treatments? On the surface, this approach seems feasible, and so it would be, if the occurrence of such accidents was high (let’s say one time in a hundred or a thousand). However, it appears that we deal with incidence rates (if there is an actual incidence) of one in several millions (i.e. very low). Therefore, any statistical pproach has a miniscule power, and a couple of “fluke accidents” (i.e., accidents that occur, let’s say in a chiropractic clinic, but in reality have nothing to do with the chiropractic treatment) may produce a “statistical error” that may persist for years in a community as small as Canada. Also, using an epidemiological approach, the question of “cause and effect” cannot be resolved.

When starting to tackle the problem of the mechanics of neck manipulative treatments three years ago with my student B. Symons (DC), we were surprised that, to the best of our knowledge, there were no data on what actually happens mechanically to the vertebral artery during cervical spinal manipulation. I was further surprised, when asked to review a case on a vertebrobasilar accident, that one of the arguments went as follows: Pathology revealed no dissection of the vertebral artery, therefore, the vertebrobasilar accident cannot be associated with chiropractic treatment.

Discussing this particular statement within the chiropractic community, it became apparent that mechanical injury to the vertebral artery was an accepted, but very, very very rare occurrence; but nevertheless, accepted. And all this without a shred of scientific evidence about the mechanics of the vertebral artery during cervical manipulation.

So, when does the vertebral artery, or for that matter, any tissue, become injured?

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What Is the Role Of Chiropractic Care in Prevention or Reduction of Musculoskeletal Injuries in Children?

By Frank M. Painter|November 19, 2012|Chiropractic Care, Pediatrics|

What Is the Role Of Chiropractic Care in Prevention or Reduction of Musculoskeletal Injuries in Children?

The Chiro.Org Blog

SOURCE: J Manipulative Physiol Ther. 2012 (Sep); 35 (7): 493–513

Chiropractic Care and Public Health: Answering Difficult Questions About Safety, Care Through the Lifespan, and Community Action

Lise Hestbaek, DC, PhD

Back and neck pain are common ailments in school age children with prevalence rates ranging from 5% to 74%. [38, 39] The prevalence of low back pain increases from preadolescence to early adulthood, [38, 40] but after that, the prevalence rates change surprisingly little. [41] A similar pattern is seen for neck pain, [41] but less is known about the course of other musculoskeletal disorders throughout life. However, extremity complaints are found frequently in children. [42]

It has been demonstrated that children and adolescents with musculoskeletal complaints have a higher risk of having these problems as adults. [43-45] Pain and aberrant musculoskeletal function are known to have other consequences with regard to health. Long-lasting pain conditions, including back pain, have been associated with a generally decreased pain threshold, [46-48] which seems to develop alongside pain, because patients did not have a higher pain threshold than asymptomatic subjects before the onset of back pain. [49] If this process is initiated in childhood, it is likely to increase the impact of minor trauma or overuse in everyday life and thus may induce a lifelong cascade of negative health events, resulting in poorer general health and lower quality of life.

Another possible consequence of musculoskeletal disorders in childhood is pain becoming a barrier to physical activity. Children who are injured while performing sport activities [42, 50] may avoid or stop the activity that caused the original injury. It is also plausible that continued pain or discomfort may reduce motivation to participate and enjoy physical activities. Reduction in activity can have serious health implications over time. It is established that physical activity is one of the most important factors relating to several lifestyle disorders such as diabetes and cardiovascular disease, [51, 52] and it has been shown that increased physical activity in youth can reduce the risk of these disorders in adulthood. [53, 54] Moreover, health habits throughout the lifespan are established in youth, [55, 56] and therefore, promoting and maintaining a healthy level of physical activity in children and adolescence are essential to improve public health. Thus, an important element to reach lifelong health is to optimize musculoskeletal health.

You may also enjoy our:

Chiropractic Pediatrics Page

(more…)

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