Chiropractic (General)

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One Voice for Chiropractic

Dear Editor:

Standard Process is proud to be a member of the Chiropractic Summit, working with 40-plus other organizations that are dedicated to unifying the chiropractic profession and helping it flourish. These organizations are working together to fulfill the mission of the summit: One Voice - One Message - Securing a Better Future. The group includes leaders of key organizations, colleges, publishers, vendors and consultants.

"One Voice" is a key concept for the Chiropractic Summit. Those of us involved in the chiropractic profession have always thought that unity would help the profession and give it the ability to express its views with a single, clear voice. That unity, in turn, would help the public and the legislature grasp and apply how chiropractic contributes to the greater good. I'm excited to report that, for the first time ever, the chiropractic profession is unifying in an unprecedented demonstration of solidarity via the Chiropractic Summit. We've had nine meetings over the past 30 months, and tremendous progress has been made toward identifying the most important issues the profession faces.

As you can imagine, legislative issues are high on the summit's agenda right now because of the impending changes in health care legislation. Recently, the summit worked closely with legislators to craft the non-discrimination language in the new health care reform bill. The summit is also working to improve practitioner participation, documentation and compliance with the Medicare system. These major accomplishments could prove to be pivotal in establishing professional parity and paving the way for chiropractors to help millions more people.

We're focused on making sure that the rights of chiropractors and chiropractic patients are protected in any change in the delivery of health care services. This work fits well with the summit's six principal concerns:

  • Help doctors feel happier and more satisfied in practice
  • Unify the profession on the most important issues, values and standards
  • Improve profitability for doctors while maintaining fair fee policies for patients
  • Inspire participation in local, state, national and international organizations
  • Address competition from other health care providers
  • Represent chiropractic properly for inclusion in national health care reform

With health care consumers eager for new answers and ready to embrace new approaches that make sense, the stage is set for chiropractors to move forward and make a bigger difference, whether in addressing painful problems or providing health and wellness services.

It's rewarding to be working with a group in which all members have a commitment to each other and the overall group goals. The ultimate beneficiaries of the Chiropractic Summit's hard work are the people in our communities, who will finally have chiropractic care available for them and their families and the ability to reap the rewards that chiropractic care provides. For more information on the Chiropractic Summit and to see a list of members, please visit www.chirosummit.org.

Charles DuBois
President,
Standard Process, Inc.


Muscle Extensibility: A Few Clarifications

Dear Editor:

I am writing in regards to your recent article, "Stretching May Increase Joint ROM Without Improving Muscle Extensibility" [May 20 issue]. It is a difficult topic to write about, but very relevant to clinical practice. Dr. Hammer made a good attempt to summarize the findings and conclusions from both the article that I co-authored, "Increasing Muscle Extensibility: A Matter of Increasing Length or Modifying Sensation?"1 as well as the clinical trial study written by Ben and Harvey,2 and he did so with an economy of space. There are, however, three issues in his article that I would like to clarify.

1. Does stretching improve muscle extensibility or not? This first issue involves a difference in terminology between these two referenced papers1-2 that may lead to confusion for your readers. The title of Dr. Hammer's article is "Stretching May Increase Joint ROM Without Improving Muscle Extensibility," and the first paragraph accurately reports this conclusion made by Ben and Harvey in their research study. The next paragraph reports the assertion made in the paper I co-authored that muscle extensibility does increase with stretching and that this may be due to modified sensation, rather than to a change in other mechanical properties of the muscle.

These two papers seem to contradict each other; does stretching increase muscle extensibility or not? The answer lies in how muscle extensibility is defined. The Ben and Harvey study defines extensibility as the ability to extend to a standardized torque. They found that extensibility measured at this standardized torque (18 Nm for this particular study) did not change after a stretching program. This finding gives some evidence that there was not a change in some passive mechanical properties (such as length and stiffness) of the stretched muscles. To my knowledge, all of the studies that report muscle extensibility does not increase with stretching use a standardized torque for an endpoint.

The muscle extensibility perspective (the paper I co-authored) defines muscle extensibility as the ability to extend to a pre-determined endpoint and that endpoint can vary depending on the intent of the study. The majority of human stretching studies use subject sensation as the endpoint of stretch application (i.e., discomfort onset, moderate stretch, pain onset, pain or stretch tolerance), and this is also an endpoint that is commonly used in clinical practice. For this reason, in the article we also suggested that the term extensibility implies a sensory endpoint in human stretching studies unless specifically stated otherwise. This usage is scientifically valid, clinically applicable, commonly used and it makes sense intuitively.

Using this terminology, we could say that Ben and Harvey also evaluated muscle extensibility using an endpoint of subject sensation - in this particular study the sensation was subjects' sensory perception of tolerance to increasing stretch application - and found that they were able to apply more torque prior to onset of the sensation. The muscles did demonstrate increased ability to extend (extensibility) using this sensory endpoint, so perception of this sensation was modified because it occurred later in the stretch application. Therefore, the findings of the Ben and Harvey study are in agreement with the sensory theory that the muscle extensibility paper proposed.

In the concluding paragraph of his article, Dr. Hammer states this also: that both of these cited papers are in agreement with each other because both suggest that the primary effect of stretching programs is modified sensation. The title of his article, however, does not reflect this conclusion.

2. What is the sensory theory? The sensory theory proposed in the muscle extensibility perspective is, as described above, that stretching modifies sensation because the selected sensation (i.e., discomfort onset, moderate stretch, pain onset, pain or stretch tolerance) occurs later in the stretch application. This sensory modification allows application of greater torque before the selected sensation is perceived, thus allowing greater muscle extensibility. The sensory theory does not suggest, as reported in Dr. Hammer's article, that increases in muscle extensibility occur because subjects "withstand increased pain." This has been specifically tested in several clinical trials,2-3 including the Ben and Harvey study; and researchers found that increases in muscle extensibility occurred because the selected sensation was perceived later in the stretch application and not because subjects tolerated a higher intensity of the selected sensation.2-3

3. Does viscoelastic deformation recover by the next stretch application? The last issue I would like to clarify is in regards to viscoelastic deformation. Dr. Hammer's article reports that viscoelastic deformation is transient and that "muscles have already recovered from the relaxation by the next stretch." I agree that viscoelastic deformation is transient; however, the duration and magnitude of the deformation are dependent upon the duration, frequency, and type of stretching applied.1 In the muscle extensibility paper, we give two examples of just how transient this deformation can be when using standard stretching doses. In these examples, it is true that the stretched muscles had already recovered from the viscoelastic deformation by the time the next stretch was applied, after a rest period of 10 or 30 seconds.1,4-5 But this is not necessarily true in all situations. For example, in studies involving cyclic stretching, there is no rest period between stretches and therefore no time for recovery from the deformation imposed by the initial stretch.6-7 In this case, viscoelastic deformation induced by preceding stretches is evident during application of each subsequent stretch.

Your publication is well-read and respected, so I think it is important to address these issues for your readers. Thank you for your consideration in this matter.

References

  1. Weppler CH, Magnusson SP. Increasing muscle extensibility: a matter of increasing length or modifying sensation? Phys Ther, 2010;90(3):438-449.
  2. Ben M, Harvey LA. Regular stretch does not increase muscle extensibility: a randomized controlled trial. Scand J Med Sci Sports, 2010;20(1):136-144.
  3. Law RYW, Harvey LA, Nicholas MK, et al. Stretch exercises increase tolerance to stretch in patients with chronic musculoskeletal pain: a randomized controlled trial. Phys Ther, 2009;89(10):1016-1026.
  4. McNair PJ, Dombroski EW, Hewson DJ, Stanley SN. Stretching at the ankle joint: viscoelastic responses to holds and continuous passive motion. Med Sci Sports Exerc, 2001;33(3):354-358.
  5. Magnusson SP, Aagaard P, Nielson JJ. Passive energy return after repeated stretches of the hamstring muscle-tendon unit. Med Sci Sports Exerc, 2000;32(6):1160-1164.
  6. Magnusson SP, Aagard P, Simonsen E, Bojsen-Moller F. A biomechanical evaluation of cyclic and static stretch in human skeletal muscle. Int J Sports Med, 1998;19(5):310-316.
  7. Taylor DC, Dalton JD, Seaber AV, Garrett WE. Viscoelastic properties of muscle-tendon units. The biomechanical effects of stretching. Am J Sports Med, 1990;18(3):300-309.

Cynthia Weppler, WPT
Niederjosbach, Germany


Handle With Care

Dear Editor:

I read with interest the article by Dr. Vasquez relating to chronic hypertension ("Chiropractors Managing Hypertension: An Idea Whose Time Has Arrived," June 17 issue). I strongly agree that chiropractors can have significant impact on helping our patients control hypertension. Although Dr. Vasquez suggested variations in clinical practice, I feel practicality of the dieting and fasting program referenced was overstated from a safety and compliance standpoint. Both studies Dr. Vasquez referenced were performed in an inpatient setting, consisted of 10 to 13.6 days of water-only fasting, had two consultations with a doctor daily, twice weekly urinalysis and weekly blood tests. This is hardly a protocol that could be incorporated into the typical chiropractic practice and any modifications of the original protocol cannot be expected to provide the same results. Lastly, there was no well-documented long-term follow-up on the results of the fast, so the effect might have been transitory.

The results of these studies, like any other study, should be viewed cautiously, as patient compliance and patient safety must be considered in the practice setting. I caution the reader to locate and study trials, regardless of subject, before accepting the results and implementing protocols into their practice.

Dwain Daniel, DC
Research Faculty Liaison
Parker Research Institute


Dynamic Chiropractic encourages letters to the editor to discuss any issue relevant to the profession, including response to articles that appeared in a previous issue of the publication. All letters should be e-mailed to editorial@mpamedia.com with "Letter to the Editor" in the subject field. Submission represents acknowledgement that your letter may appear in a future issue of DC, but does not guarantee publication.

September 2010
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