Spinal Manipulation for Back and Neck Pain: Does It Work?

Spinal Manipulation: A Valid Technique?

In her office at McMaster University in Toronto, Anita Gross, MSc, has logged paper after paper showing that spinal manipulation can help control neck pain. “The evidence keeps growing and growing,” she says.

Gross, a physiotherapist and associate professor of rehabilitation science, helped write a 2015 Cochrane review of the literature and is already at work on updating that paper.[1]

Mounting evidence also supports spinal manipulation for low back pain, says Roger Chou, MD, professor of medicine at Oregon Health & Science University in Portland, Oregon, who led a similar review for the Agency for Healthcare Research and Quality last year.[2]

Orthopedists can confidently refer many neck and back patients for this type of treatment when surgery is not indicated, these and other experts agree. The findings counter decades of accusations of quackery mounted against healers who massage or manipulate patients’ muscles or joints.

But other therapies, particularly exercise, may work just as well. And the research so far leaves big questions unanswered. For example, does one technique for spinal manipulation work better than another? What is the mechanism of these techniques? Are patients better off being treated by physical therapists, chiropractors, osteopathic physicians, massage therapists, or some other category of practitioner? How long should a patient keep trying spinal manipulation before deciding that no more benefits are likely?

Osteopathic vs Chiropractic Approaches

Spinal manipulation—along with manual therapy involving other anatomical structures—has evolved over thousands of years, starting with bone-setting practices that probably preceded recorded history. Mention can be found in ancient Egyptian and Chinese texts, as well as in the writings of Hippocrates.[3,4]

Two prominent traditions in the United States arose in the late 19th century, when Andrew Taylor Still, MD, a physician and surgeon, founded osteopathy and osteopathic medicine, and Daniel David Palmer, a practitioner of magnet healing (a pseudoscientific alternative medicine practice), founded chiropractic.

These founders cited different influences: Palmer ascribed his knowledge to visitations from the spirit world,[5] whereas Dr Still made a more conventional study of both allopathic and alternative medicine current in his day. (Because Dr Still’s publications preceded Palmer’s, some authorities have speculated that Palmer based his approach on Dr Still’s.[3]) The founders of both modalities believed that they could treat not only joint and muscle pain, but also many other apparently unrelated ailments.

Perhaps because of the differences in their founders’ inspirations, chiropractic and osteopathy have diverged. In the United States, schools of osteopathy now resemble allopathic medical schools, although musculoskeletal manipulation therapy remains part of the curriculum. Osteopathic physicians in the United States have the same scope of practice as medical doctors. Many don’t practice manual therapy at all, and most of those who do confine those therapies to treatment of musculoskeletal and neuromuscular disorders. In many other countries, there are osteopaths who practice manual therapies but not medicine.

Chiropractors in most US states cannot prescribe drugs or perform surgery. Some focus entirely on manual therapy, whereas many others incorporate other modes of alternative medicine into their practices, such as herbal medicine or acupuncture. Some chiropractors confine themselves to musculoskeletal and neuromuscular disorders, especially for back pain, but others treat a broader range of disorders.

Physical therapists and physiatrists may also use manual therapy, including spinal manipulation, among other techniques.

Unknown Mechanisms of Action

Researchers have distinguished between manipulation and mobilization. Anita Gross, the Canadian researcher, describes mobilization as a “slow, sustained, or repeated type of movement.” Most of what massage therapists do fits into this category. Manipulation, on the other hand, is “a more high-velocity quick stretch at the end of a range.” Chiropractors are particularly associated with this type of therapy.

No one knows for sure why spinal manipulation works. Palmer said chiropractic manipulation corrects subluxations—misalignments of vertebrae that impinge nerves. Dr Still contended that osteopathic manipulation improved circulation.

Contemporary theories on the mechanism of spinal manipulation include the disruption of articular or periarticular adhesions; release of entrapped synovial folds; unbuckling of motion segments that have undergone disproportionate displacements; relaxation of hypertonic muscle; alteration of mechanoreceptors in the spinal apophyseal joints; and release of endorphins.[6]

However spinal manipulation works, it’s at least better than nothing when it comes to chronic low back pain, says Dr Chou. “Our general finding was that manipulation appears to be more effective than treatments that are thought to be basically control treatments—such things as pretend ultrasound or giving somebody an educational booklet,” he explains.

It’s hard to say whether spinal manipulation is significantly better than other noninvasive, active treatments for chronic low back pain. Effect sizes for all of these therapies are small. Spinal manipulation “seems to be similar in effectiveness to such things as exercise, which is probably the thing that it has been most commonly compared with,” Dr Chou says.

The few trials that looked at radicular low back pain, however, found that spinal manipulation was not effective.

The effects of spinal manipulation appeared to be not only modest but also short in duration. And there was some evidence that spinal manipulation might work best in combination with other therapies.

For example, in one trial that Dr Chou says was good-quality, patients who had spinal manipulation plus home exercise and advice reported after 12 weeks that their pain was about 1 point lower on a scale of 0-10 than did patients who exercised and got advice without spinal manipulation. After 1 year, though, the difference faded to less than 0.7 point and was no longer significant.[2]

Evidence for Cervical Manipulation

Gross and her colleagues reached similar conclusions about improving pain, function, and quality of life related to neck complaints. “There is some immediate pain relief—not necessarily long-term,” she says. And most of the evidence was for chronic rather than acute symptoms.

Results for mobilization and manipulation were similar, and both might work best in combination with exercise. “Across our different Cochrane reviews, we can say that probably the combination of manual therapy and exercise seems to be a dominant piece that’s coming out as being a wise choice,” Gross says.

In acute and subacute neck pain, cervical manipulation was more effective than various combinations of analgesics, muscle relaxants, and nonsteroidal anti-inflammatory drugs for improving pain and function in the short and intermediate term. The evidence for treating neck pain with cervical spinal manipulation was not as strong as the evidence for treating it with thoracic spinal manipulation, Gross and her colleagues found.[1]

But the research left many gaps. Spinal manipulation is difficult to study because patients and practitioners can’t be effectively blinded to the treatment. Most effects are subjective. And it’s hard to standardize treatments from one practitioner to another. “This is more complicated than looking at whether acetaminophen works, for example,” says Dr Chou.

In part for this reason, the researchers couldn’t find much evidence for the superiority of any particular spinal manipulation technique or any category of practitioner. Nor could they determine the optimum frequency or duration. “In the trials that have been done, it’s hard to see clear differences, whether it’s chiropractic or osteopathy, or whether somebody is doing it once vs five times a week,” Dr Chou says.

Dr Chou doesn’t practice any manual therapies, and his research has extended to all noninvasive therapies for low back pain. He considers exercise and cognitive-behavioral therapy as first-line therapies for chronic low back pain. “I view manipulation and such things as acupuncture as being more passive” on the part of the patient, he says. “Active treatments get people engaged and involved in their care.”

When to Refer, and to Whom

Many people with low back pain are afraid to move. But bed rest causes deconditioning that can actually increase the risk for further injury, Dr Chou says. By prescribing both exercise and cognitive-behavioral therapy, a physician can “get the muscles and soft tissues moving, and get people to understand that if they have some pain, that’s not a bad thing.”

When he does refer patients for spinal manipulation, Dr Chou tries to make sure the practitioner is not going to apply additional therapies that are unproven. “There are some chiropractors who do manipulation, and they are also doing things that may be counterproductive, such as getting radiography that isn’t necessary and telling people there is something wrong with their alignment that makes people worry about things they shouldn’t be worried about,” says Dr Chou. “Those are folks I try to avoid if I can.”

He advises patients to try spinal manipulation for 3-4 weeks, then move on to something else if it isn’t helping. But he acknowledges that he has no research to support that recommendation.

Gross, who practices manual therapy, refers practitioners to an online “neck pain toolkit” developed by a collaboration of physiotherapists.[7] For low back pain, she recommends “Low Back Pain Strategy,” a similar resource developed by the Ontario Ministry of Health and Long-Term Care.[8] But she adds that no literature review or evidence-based algorithm can provide all of the guidance a practitioner needs to treat a patient’s back or neck pain.

The decision to use spinal manipulation “always has to be based on more than just research evidence,” Gross insists. “It has to be based on good sound clinical reasoning, biology, the psychosocial elements around you, and the individual you are helping.”

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