Mightier Than the Sword — Using Research to Promote and Defend Chiropractic

The Chiro.Org Blog


By Daniel Redwood, DC

If the public is to be better educated about the benefits of chiropractic care, doctors of chiropractic must be the ones to do the educating. Research is the strongest tool we have to promote our healing art to those unfamiliar with its value and to defend it from unwarranted attacks. We owe it to our patients, our profession, ourselves and future generations to know the facts so that we can share them far and wide.

This does not mean that every practicing DC needs to become a full-time scholar, familiar with the details and nuances of the approximately 100 randomized clinical trials on spinal manipulation. It does mean that to be effective chiropractic ambassadors, we all need a good grasp of the overall picture, along with working knowledge of a small number of studies, reviews and guidelines that will allow us to most effectively deliver our message. And we need to stay up-to-date as new studies emerge.

For much of our history, prior to the dawn of the modern era of chiropractic research in the 1970s and 1980s, DCs had no choice but to rely completely on powerful, true stories about the patients we had helped in our offices. These individual stories still matter and can legitimately be shared with others as part of our outreach.But in this evidence-based era, we must use these anecdotes as the spice only, rather than the main course. Otherwise, we risk losing many opportunities to strengthen our case through strategic use of the increasingly broad and deep body of evidence researchers have made available to us. We best honor their work by sharing it widely, forcefully and accurately.

1.   Low-Back Pain

How do we spread a positive message about chiropractic while remaining faithful to the facts, neither overstating nor understating the research data? Let’s start with the condition seen most often by DCs—low-back pain (LBP).

Can we legitimately claim that spinal manipulation (used here as a synonym for chiropractic adjustment) is “of proven benefit” for LBP? To answer this question, we need to ask a preliminary question: What kind of evidence is sufficient? To convince those who are not already supporters of chiropractic (particularly other health professionals in our communities and policy makers in government and industry), we need to see at least a modest number of positive randomized controlled trials (RCTs) and ideally the endorsement of spinal manipulation in systematic reviews and/or evidence-based practice guidelines.

For LBP, we surpassed this threshold at least 15 years ago. There are now several dozen RCTs on spinal manipulation for LBP, the majority of which prove a significant benefit from spinal manipulation, the mainstay (but not the entirety) of chiropractic care. More often than not in these clinical trials, manipulation has outperformed comparison therapies or a placebo. Since at least the mid-1990s, when the U.S. Agency for Healthcare Policy and Research released its landmark guidelines on acute LBP, [1] which identified spinal manipulation as the only doctor-delivered method shown to both relieve pain and improve function, it is clear that any evidence-based guidelines process must recognize the effectiveness of spinal manipulation for LBP. While guidelines [2, 3] from chiropractic organizations like the Council on Chiropractic Guidelines and Practice Parameters (CCGPP) are among our profession’s most important initiatives and merit our strong support, guidelines prepared by non-chiropractors carry more weight in our interactions with those outside the profession because they can more readily withstand accusations of bias, however unjustified these might be.

At this time, the strongest single fact we can cite in support of the effectiveness of spinal manipulation is that the 2007 LBP guidelines [4] jointly prepared by the American College of Physicians and the American Pain Society identify spinal manipulation as a method “of proven benefit” for acute, subacute and chronic LBP. While the ACP-APS guidelines recognize several “nonpharmacologic” methods (intensive interdisciplinary rehabilitation, exercise therapy, acupuncture, massage therapy, spinal manipulation, yoga, cognitive-behavioral therapy, and progressive relaxation) as effective for subacute and chronic cases, only spinal manipulation is also recognized as effective for acute LBP.

In this cost-conscious time, DCs should know that a recent review [5] on the cost-effectiveness of methods endorsed in the ACP-APS guidelines found that spinal manipulation was money-saving for treatment of subacute and chronic LBP, and that there was insufficient evidence to reach a conclusion about its cost-effectiveness for acute cases. To put this into context, the review also found that there was no evidence at all on the cost-effectiveness of medications for LBP of any duration. When facing questions about chiropractic’s advantages, this fact should always be noted.

DCs should also be aware that the ACP-APS guidelines include some recommendations with which we disagree (i. e., prioritizing pain medications as a first-line, self-care approach that should precede a referral for spinal manipulation). Nonetheless, the fact that the widely recognized ACP-APS guidelines conclude that manipulation is effective carries a “final verdict” kind of power that we should all be ready to quote early and often.

While the ACP-APS guidelines may be our strongest ally in policy settings, there is great power in sharing some of the dramatic specifics from individual studies. With so many studies available on LBP, individual DCs may differ as to which two or three to cite. I often quote the early studies by Kirkaldy- Willis and Cassidy [6] and Meade [7, 8] (both involving orthopedic surgeons who found chiropractic care extraordinarily effective). Others on my personal highlight reel are the large and influential U.K. BEAM study, [9, 10] which demonstrated both effectiveness and cost-effectiveness; and the smaller Wilkey et al. Trial [11] on chronic LBP, performed inside the British National Health Service, where chiropractic yielded five times as much improvement on disability measures as that achieved by conventional medical care.

In addition, every DC worldwide should be familiar with the award-winning 2010 study by Bishop and colleagues, [12] which shows that guidelines-based care including chiropractic spinal manipulation is far more effective than “usual care” from family practice MDs. The study also shows that typical medical care is poorly adherent to guidelines, with 78 percent of medical patients receiving prescriptions for narcotics (i. e.,Tylenol 3 with Codeine), which are not guideline-endorsed.

2.   Low-Back Pain With Sciatica

An important subset of LBP cases involves disc-related sciatica. The research on this is far less extensive than for LBP without leg pain, but two major RCTs have demonstrated very positive responses to chiropractic care. The Santilli et al. Trial, [13] written by three MDs about care delivered by DCs, found that acute lumbar disc syndrome responded far better to spinal manipulation than to sham manipulation, while the McMorland et al. Study [14] (with a DC as lead author and three neurosurgeons as coauthors) found that 60 percent of patients who would otherwise have been sent for microdiskectomy achieved equivalent outcomes through chiropractic, and were thus able to avoid surgery. Anytime you are confronted with an assertion that chiropractic may be appropriate for LBP but not if sciatica is involved (as still happens frequently, in person and in print), citing the Santilli and McMorland studies is the strongest response.

3.   Neck Pain

Once we move beyond the impressive research on LBP, evidence for the effectiveness of spinal manipulation grows thinner. It is important to remember that for neck pain, research on all conventional and alternative approaches, not just those used by doctors of chiropractic, is far more limited than for LBP. At this point, there is at least as much evidence supporting manual therapies for neck pain (particularly when combined with exercise) as for any other approach. Unfortunately, no method has strong research support.

By far the most comprehensive recent evaluation of all neck pain therapies was that performed by the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders, chaired by Scott Haldeman, DC, MD, PhD. In the panel’s report on noninvasive interventions, it concluded: “Our best evidence synthesis suggests that therapies involving manual therapy and exercise are more effective than alternative strategies for patients with neck pain; this was also true of therapies which include educational interventions addressing self-efficacy.” Because DCs consistently include exercise advice and share relevant self-care educational materials with patients as part of overall care, chiropractic management of neck pain substantially embodies the full range of noninvasive therapeutic approaches recommended by the Bone and Joint Decade Task Force.

Overall, however, the task force concludes that most cases of neck pain should be expected to recur and that even those therapies shown to be effective have not demonstrated long-term benefits.

Probably the most positive RCT on chiropractic care for neck pain is the one performed by Palmgren et al. [15] in Sweden. They found that a group of chronic neck pain patients who received 15 to 25 chiropractic treatments over a five-week period had significantly lower pain scores and greater head repositioning accuracy than another group with the same condition given a similar examination but no treatment.

4.   Headaches

Numerous studies have shown spinal manipulation to be an effective treatment for headaches. As holistic physicians, DCs recognize that headaches can develop from a variety of causes, alone or in combination. Such causes may include spinal joint dysfunction, muscular imbalance and tension, negative reactions to foods or medications, sleep disturbances, emotional stress or chemical irritants in the water or air.

The most recent systematic review of the research on manual interventions for headaches, [16] led by Roland Bryans, DC, of the Canadian Chiropractic Association/Federation Clinical Practice Guidelines Project, concludes that manipulation can be recommended for cervicogenic headaches and for episodic and chronic migraines. It finds mixed evidence on manipulation for tension-type headaches (TTH) and refrains from any recommendation on chronic TTH, while stating that manipulation “cannot be recommended” for episodic TTH.

Perhaps the best known clinical trial on chiropractic and TTH was the Boline et al. [17] study that compared chiropractic care to the medication amitriptyline. These investigators found that one month of chiropractic care (approximately two visits per week) was more effective than amitriptyline for long-term relief of headache pain. During the treatment phase of the trial, pain relief among those treated with medication was roughly comparable to relief in the chiropractic group. But chiropractic patients maintained their levels of improvement after treatment was discontinued, while those taking medication returned to pretreatment status an average of four weeks after its discontinuation.

For cases of migraine, the studies by Nelson et al. [18] (structured in A manner similar to the Boline study on manipulation vs. amitriptyline) and Tuchin et al. [19] (in which manipulation was compared to a detuned ultrasound placebo) provide good support.

For cervicogenic headache, the Nilsson et al. [20] trial may be the best for buttressing our case. Researchers compared groups given either high-velocity cervical spinal manipulation or low-level laser treatment and found statistically significant improvement for the manipulation group in terms of decreased pain, headache hours per day and use of pain medication.

Aside from proving efficacy or effectiveness, research can help clinicians plan evidence based courses of care. A particularly helpful perspective for DCs seeking a better understanding of how to manage headache cases can be gained from a dose response study by Haas et al. [21] Seeking to determine the proper frequency of chiropractic treatments for headache patients, these researchers randomly allocated 24 adults with cervicogenic headache into groups visiting a doctor of chiropractic one, three or four times per week over a four-week period.

All patients received high-velocity, low-amplitude adjustments plus up to two physical modalities including heat and soft-tissue therapy. Greater pain relief was seen at four and 12 weeks for the patients receiving nine and 12 treatments than for those receiving three, demonstrating that continuing treatments for up to 12 treatments conferred additional benefits.

5.   Extremity Conditions

The evidence for manipulation in extremity conditions is more limited than for LBP, neck pain and headaches. The best strategy in speaking about this research is probably to say that there are some clinical trials showing that manipulation (i. e., of the extremity and the full kinetic chain) can help various conditions but that for chiropractic care and all other forms of care, research is in an early phase. As is the case for other musculoskeletal conditions, a judicious blend of manipulation, mobilization and exercise is often the best course.

The two major systematic reviews on chiropractic care for extremity conditions are the UK Evidence Report [22] by Bronfort et al. (for both upper and lower extremities) and Brantingham’s CCGPP review [23] (lower extremity only). There is at least a single positive clinical trial (and in some cases a few RCTs) for disorders of the shoulder, hip, knee, ankle and foot. Space does not permit further detail here, but DCs seeking to make a research-based case for extremity care should, at a minimum, read the extremity sections of these reviews.

6.   First Prevention Study

One unique lower extremity study, the first ever to demonstrate preventive effects of chiropractic care, is the Hoskins and Pollard trial, [24] in which adding chiropractic care to standard medical and physical therapy approaches dramatically decreased the number of leg injuries and missed games among Australian professional football players. Every chiropractor who works with athletes should know this study from start to finish. It is groundbreaking and packs extraordinary power.

7.   Nonmusculoskeletal Conditions

Virtually every doctor of chiropractic has seen cases where a visceral disorder improves, sometimes quite dramatically, under chiropractic care. From D.D. Palmer onward, generalized claims of chiropractic’s effectiveness for visceral disorders have arguably been the single greatest source of conflict between practitioners of chiropractic and medicine. It is therefore essential that we understand what current research says, and does not say, about somatovisceral disorders.

First, there is no visceral disorder for which research has shown a consistent benefit from spinal manipulation or chiropractic care. We may wish that it did, but it does not. Claims to the contrary quickly diminish the credibility of the doctor making the claim.

This does not mean, however, that chiropractic care cannot benefit certain individuals with visceral disorders.

There are countless case reports, and a small number of case series, in the literature. When it comes to randomized controlled trials, there are currently only two positive examples—the Wiberg study on infantile colic [25] and the Bakris-Dickholtz [26] study on hypertension. Large, well-publicized trials on asthma [27] and dysmenorrhea [28] failed to show a benefit from spinal manipulation, though the placebos used in both studies have come under strong criticism.

Two systematic reviews, by Bronfort et al. [22] and Hawk et al., [29] address nonmusculoskeletal disorders. The Hawk et al. Review, which employs a whole systems research perspective not limited to RCTs, concludes that “evidence from controlled studies and usual practice supports chiropractic care (the entire clinical encounter) as providing benefit to patients with asthma, cervicogenic Vertigo, and infantile colic,” and that “evidence was promising for potential benefit of manual procedures for children with otitis media and elderly patients with pneumonia.”

Research remains our strongest tool for promoting and defending chiropractic, but only if we quote it accurately. Our future progress depends in large measure on our willingness to make the necessary effort.

Daniel Redwood, DC, is a professor at Cleveland Chiropractic College and a member of the ACA Publications Board. He serves on the Chiropractic Summit Government Affairs Committee and the editorial boards of The Journal of Alternative and Complementary Medicine and Topics in Integrative Healthcare.


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