Spinal manipulation in the treatment of musculoskeletal pain

Spinal manipulation in the treatment of musculoskeletal pain


Author
Paul Shekelle, MD
Section Editor
Steven J Atlas, MD
Deputy Editor
H Nancy Sokol, MD

Last literature review version 16.2: May 2008 | This topic last updated: October 19, 2007

INTRODUCTION — Spinal manipulation is a technique used by chiropractors, physical therapists, and osteopathic physicians, primarily, to provide relief for musculoskeletal pain related to the back and neck. It has also been used for other conditions, which are discussed briefly below.
This topic will focus on a description of spinal manipulation, and a discussion of its effectiveness. Detailed discussions concerning the approach to and treatment of the patient with back and/or neck pain is presented separately. (See "Treatment of acute low back pain" and see "Evaluation of the patient with neck pain and cervical spine disorders").

SPINAL MANIPULATION — Spinal manipulation is a form of manual therapy that involves the movement of a joint beyond its usual end range of motion but not past its anatomic range of motion, an area which has been termed the "paraphysiologic zone." This movement of the joint is frequently accompanied by an audible cracking or popping sound.

Types of manipulation — Spinal manipulation is classified into one of two forms, depending upon the lever arm used to help the practitioner apply the load necessary for the manipulation:

The first type includes long lever, low velocity, or nonspecific manipulations; this form uses one of the long bones of the limbs (frequently the femur) to amplify the load applied by the clinician's hands to one or several spinal joints. These manipulations are associated primarily with the practice of osteopathy and physical therapy [1,2] .

The second type includes short lever, high velocity manipulations, or specific spinal adjustments; this form involves a short forceful thrust on a specific vertebral transverse process, thereby moving the specific joint. These manipulations are generally associated with the practice of chiropractic.
Postulated mechanisms of benefit — Four hypotheses have been proposed to explain the benefits of manipulation:

• Release of entrapped synovial folds or plica
• Relaxation of hypertonic muscle by sudden stretching
• Disruption of articular or periarticular adhesions
• Unblocking of motion segments that have undergone disproportionate displacements.

Although some research supports each of these hypotheses, there is no convincing evidence proving the pathophysiologic mechanism underlying the benefit of spinal manipulation.

LOW BACK PAIN — Spinal manipulation is used for the treatment of both acute and chronic back pain. Manipulation is safe and probably effective for patients without radiculopathy, however the beneficial effect may be minimal [3] . A meta-analysis of randomized, controlled trials concluded that there is no evidence that spinal manipulation is superior to other standard treatments for low back pain [4] . Spinal manipulation was superior to sham therapy and to therapies that have been judged to be ineffective or harmful, but had no advantage when compared with general practitioner care, analgesics, physical therapy, exercises, or back school. Results were similar for acute and chronic low back pain.

Trials subsequent to this meta-analysis have come to similar conclusions. A randomized trial of adding spinal manipulation to "best care" in general practice for patients with low back pain in the United Kingdom found a very small benefit of questionable clinical significance [5] . Another trial in the UK found no difference in outcome in patients with acute nonspecific low back pain randomly assigned to receive spinal manipulation or a brief pain management program [6] .

It may be possible to define subsets of patients in whom manipulation is likely to be beneficial. A randomized trial found that patients with low back pain were much more likely to benefit from manipulation plus exercise than from exercise alone, if they met at least four of the following criteria [7] :

• Symptoms for fewer than 16 days
• No symptoms distal to the knee
• A score below 19 on the Fear-Avoidance Beliefs Questionnaire
• At least one hypermobile segment in the lumbar spine
• At least one hip with more than 35 degrees of internal rotation

Thus, there are sufficient data to conclude that lumbar spinal manipulation is mildly effective for some patients with low back pain; the data are strongest for patients with acute uncomplicated low back pain. At present, we consider it appropriate to recommend manipulation as a therapeutic option to patients with uncomplicated low back pain who cannot take or tolerate other pain relieving measures (such as acetaminophen or NSAIDs), those who responded well to manipulation in the past, or patients whose symptoms have persisted at an unacceptable level for more than 10 days. The effectiveness of manipulation relative to other forms of therapy remains a subject for ongoing research.

Chiropractic care for low back pain probably costs more than supportive care provided by medical doctors, but it is also associated with enhanced patient satisfaction. The costs of chiropractic care and physical therapy are similar [8] . However, there are some data that patients who have insurance coverage for chiropractic care may have lower total health care expenditures, perhaps because of lower utilization of imaging and invasive procedures [9] ; an alternative explanation for these data are that healthier patients may tend to choose a plan with chiropractic coverage [10] . No data exist to suggest that spinal manipulation can help prevent future back pain.

(See "Treatment of acute low back pain" and see "Subacute and chronic low back pain: Pharmacologic and noninterventional treatment").

NECK PAIN AND HEADACHE — After low back pain, neck pain and headache are the next most common symptoms for which spinal manipulative therapy is offered. Together, these symptoms account for about 20 percent of all visits to chiropractors. It is estimated that between 18 and 38 million cervical spine manipulations are performed annually in the United States [11,12] .

Efficacy of manipulation for neck pain — The data supporting the efficacy of spinal manipulation for neck pain are more limited than those for low back pain, and the quality of these studies is insufficient to draw firm conclusions [13] . As an example of studies in support of spinal manipulation, one randomized study compared physical therapist provided manipulation to nonmanipulative physical therapy, heat, or usual general practitioner care for patients with either non-specific low back or neck pain syndromes [14] . This study concluded that both physical therapist treated groups had better patient outcomes than the other two groups; in addition, the group receiving manipulation therapy did slightly better at one year than the group that received nonmanipulative physical therapy.

Similarly, a randomized trial in the Netherlands that compared manual therapy (including cervical spine mobilization but not high velocity manipulation) to either physical therapy or standard care by a general practitioner concluded that manual therapy was superior [15] . At seven weeks, success rates for manual therapy, physical therapy, and care by a general practitioner were 68.3, 50.8, and 35.9 percent respectively. Manual therapy (that excluded spinal manipulation) was significantly less expensive than physical therapy or care by a general practitioner, making it more cost-effective than either [16] .

In contrast, a randomized trial comparing spinal manipulation, physiotherapy, and intensive training for patients with chronic neck pain found no difference among the three groups [17] . Another randomized trial compared manual therapy that involved high velocity cervical spine manipulation with manual therapy that involved gentle neck mobilization over the patient's passive range of motion [18] . Manipulation was no better than gentle mobilization.

A Cochrane review concluded that manipulation and/or mobilization were not beneficial when done alone, but they were beneficial when used with exercise [19] . The review also concluded that neither manipulation nor mobilization was superior to the other and that there was insufficient evidence about their effects in patients with radicular findings. The review acknowledged the methodologic limitations of many of the underlying trials, and we feel that the evidence remains inadequate to draw firm conclusions.

Efficacy of manipulation for headache — There are very limited data supporting the use of manipulation of the cervical spine for headache. In one study, for example, the use of cervical spine manipulation for the treatment of episodic tension-type headache was found to be no better than soft tissue massage or placebo laser therapy [20] . A second short-term study of spinal manipulation for chronic tension-type headache reported statistically significant improvements for some but not all outcome measures in the manipulated group compared to a group of patients treated with amitriptyline [21] .

Two clinical trials of cervical spine manipulation for patients with migraine headache found no benefit compared to either spinal mobilization exercises or the use of amitriptyline [22,23] . A systematic review published in 2002 concluded that there were insufficient data to support the proposition that spinal manipulation is beneficial for treating headache [24] .

Summary — At the present time, we do not recommend manipulation of the cervical spine because the benefit is unproven and there are rare but serious adverse effects associated with neck manipulation (see below). Patients treated with gentle mobilization appear to do as well as those treated with high velocity manipulation [18] .

OTHER CLINICAL CONDITIONS — A randomized trial in 150 patients with shoulder pain and dysfunction found that compared with usual care, patients treated with manipulation of the cervical spine, upper thoracic spine, and adjacent ribs had higher rates of improvement after 12 weeks of treatment [25] . The study was unblinded and examined the primary outcome (patient perceived recovery) at a number of points in time without adjusting for multiple testing.

Chiropractic spinal manipulation does not appear to provide additional clinical benefit for the medical treatment of asthma in children [26] . At present, there are no compelling data supporting the efficacy of spinal manipulation for nonmusculoskeletal disorders.

RISKS OF SPINAL MANIPULATION — In general, spinal manipulation is felt to be a relatively safe procedure, although it may be associated with a number of minor complaints and, rarely, serious adverse events.

Minor complaints — Minor complaints following spinal manipulation are common. One systematic review of five prospective studies concluded that mild to moderate transient adverse reactions occurred in one-half of all patients undergoing spinal manipulation [27] . In the largest series included in this review of 1,058 patients treated by chiropractors, approximately 12, 11, and 50 percent of patients complained of headache, fatigue, and local discomfort at the site of the manipulation, respectively [28] . Other less frequent complaints included dizziness, nausea, and hot skin. The causal relationship between spinal manipulation and any of these symptoms is unknown.

A randomized trial of manipulation for neck pain found that low velocity manipulation (mobilization) was somewhat less likely than high velocity manipulation to lead to adverse reactions, however adverse reactions were common in both groups, occurring in 30 percent of patients [29] . Increased neck pain or stiffness was the most common adverse event, occurring in 25 percent of patients.

Serious adverse events — The most common serious adverse events associated with spinal manipulation include disk herniation, the cauda equina syndrome, and vertebrobasilar accidents. Estimates of the incidence of these complications range from 1 per 2 million to 1 per 400,000 manipulations [30] . These estimates are primarily derived from published case reports, case series, and retrospective surveys, all of which may be unreliable due to underreporting and the dependence on recall.

Disk herniation and the cauda equina syndrome occur most commonly with lumbar manipulation [31] . Individuals with a herniated nucleus pulposus or an underlying bleeding disorder are postulated to be at increased risk of the cauda equina syndrome.

Vertebrobasilar artery ischemic events occur after cervical manipulation [32] . Some reports estimate it to occur as infrequently as once per 1 to 3 million manipulations [13] , while others report an incidence as high as 1.3 per 100,000 manipulations [33] .

A six week prospective study of cervical spine manipulation involved 377 chiropractors in Britain (32 percent of the country's chiropractors, although all were invited to participate), and over 19,000 patients and 50,000 cervical manipulations [34] . No serious adverse events were reported by clinicians or patients in this timeframe, although underreporting was possible both due to loss to follow-up for 413 consultations, and potential bias introduced by self-reporting.
A population-based, case-control study found that in patients under the age of 45, those with vertebrobasilar dissection or occlusion were five times more likely than controls to have visited a chiropractor in the previous week and to have had three or more cervical chiropractic visits in the previous month [33] . No association between chiropractic and vertebrobasilar events was found for older individuals. Similarly, a case-control study of patients younger than 60 presenting with a stroke or transient ischemic attack found a higher rate of spinal manipulation within the previous 30 days in patients whose event was due to a vertebral arterial dissection than in patients with an event due to another etiology (odds ratio 6.62, 95% CI 1.4-30) [35] .

A paucity of data exists concerning the risk factors for vertebrobasilar compromise after manipulation. Anecdotal evidence suggests that the risk is higher for manipulation involving rotation plus extension of the cervical spine than for other types of manipulation.

Other — There are many case reports describing complications due to misdiagnosis by providers who perform spinal manipulation, such as failing to correctly diagnose spinal tumors or metastatic disease.