Many therapies exist for the treatment of low-back pain including spinal manipulative therapy (SMT), which is a worldwide, extensively practiced intervention. This report is an update of the earlier Cochrane review, first published in January 2004 with the last search for studies up to January 2000.
To examine the effects of SMT for acute low-back pain, which is defined as pain for less than six weeks duration.
A comprehensive search was conducted on 31 March 2011 in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, PEDro, and the Index to Chiropractic Literature. Other search strategies were employed for completeness. No limitations were placed on language or publication status.
Randomized controlled trials (RCTs) which examined the effectiveness of spinal manipulation or mobilization in adults with acute low-back pain were included. In addition, studies were included if the pain was predominantly in the lower back but the study allowed mixed populations, including participants with radiation of pain into the buttocks and legs. Studies which exclusively evaluated sciatica were excluded. No other restrictions were placed on the setting nor the type of pain. The primary outcomes were back pain, back-pain specific functional status, and perceived recovery. Secondary outcomes were return-to-work and quality of life. SMT was defined as any hands-on therapy directed towards the spine, which includes both manipulation and mobilization, and includes studies from chiropractors, manual therapists, and osteopaths.
DATA COLLECTION AND ANALYSIS:
Two review authors independently conducted the study selection and risk of bias (RoB) assessment. Data extraction was checked by the second review author. The effects were examined in the following comparisons: SMT versus 1) inert interventions, 2) sham SMT, 3) other interventions, and 4) SMT as an additional therapy. In addition, we examined the effects of different SMT techniques compared to one another. GRADE was used to assess the quality of the evidence. Authors were contacted, where possible, for missing or unclear data. Outcomes were evaluated at the following time intervals: short-term (one week and one month), intermediate (three to six months), and long-term (12 months or longer). Clinical relevance was defined as: 1) small, mean difference (MD) < 10% of the scale or standardized mean difference (SMD) < 0.4; 2) medium, MD = 10% to 20% of the scale or SMD = 0.41 to 0.7; and 3) large, MD > 20% of the scale or SMD > 0.7.
We identified 20 RCTs (total number of participants = 2674), 12 (60%) of which were not included in the previous review. Sample sizes ranged from 36 to 323 (median (IQR) = 108 (61 to 189)). In total, six trials (30% of all included studies) had a low RoB. At most, three RCTs could be identified per comparison, outcome, and time interval; therefore, the amount of data should not be considered robust. In general, for the primary outcomes, there is low to very low quality evidence suggesting no difference in effect for SMT when compared to inert interventions, sham SMT, or when added to another intervention. There was varying quality of evidence (from very low to moderate) suggesting no difference in effect for SMT when compared with other interventions, with the exception of low quality evidence from one trial demonstrating a significant and moderately clinically relevant short-term effect of SMT on pain relief when compared to inert interventions, as well as low quality evidence demonstrating a significant short-term and moderately clinically relevant effect of SMT on functional status when added to another intervention. In general, side-lying and supine thrust SMT techniques demonstrate a short-term significant difference when compared to non-thrust SMT techniques for the outcomes of pain, functional status, and recovery.
SMT is no more effective in participants with acute low-back pain than inert interventions, sham SMT, or when added to another intervention. SMT also appears to be no better than other recommended therapies. Our evaluation is limited by the small number of studies per comparison, outcome, and time interval. Therefore, future research is likely to have an important impact on these estimates. The decision to refer patients for SMT should be based upon costs, preferences of the patients and providers, and relative safety of SMT compared to other treatment options. Future RCTs should examine specific subgroups and include an economic evaluation.
“Spinal manipulative therapy” in this review, which was pretty exhaustive, included both manipulation (frequently used by chiropractors, but also osteopaths and more and more physical therapists) are the high velocity short amplitude thrusts that often result in that audible “crack.” Mobilizations are usually of larger ranges of motion with slower passive movements, popularized among physical therapists by Geoffrey D. Maitland. What does it matter you ask? Not much because according to this Cochrane review neither have any effect, at least compared to sham (fake treatment) or placebo (also fake treatment) with regards to lessening pain or disability in those with acute (less than 6 weeks) low back pain.
I talk with patients and colleagues about manipulation and mobilizations all the time and often say, given what we know about the mechanisms and causes of spinal pathologies (excluding magic or placebo), what would or even what could a manipulation/mobilization do? Funny that I never get an answer. You would think a doctor who uses such methods (DC, DPT or DO) could answer that. This paper said it MIGHT work by two principle means. One mechanical mode of action to lessen a vertebral subluxation, is a hypothesis which has already been largely discredited. The second being neurophysiologic explanation that just sounds like a weak use of gate control theory, which does seem to be a real phenomenon, but whether manipulations/mobilizations can effectively exploit gate control theory is another matter. The authors concluded the mechanism of action was “remains debatable” but considering the primary finding of this review I think a better question is, “since back pain isn’t reduced any better than with a sham/placebo treatment, is there any further mechanism of action that needs explaining?” To me saying, “it’s probably all in your head” really sums it up best.
Another interesting finding was that though manipulation and mobilization didn’t work any better than sham or placebo treatments, it compared favorably to other conventional treatments for low back pain. This was puzzling to the authors. I have already blogged on Mckenzie Method of physical therapy with research showing that it was no more effective than advice to stay active, but better than Williams flexion stretches. I often comment that if you go to a Chiropractor for manipulation for low back pain he may not help you but at least he won’t make you worse. Contrast this with a lot of physical therapists who are going to treat back pain with a lot of stretching, often immediately having the patient lay on their back and stretch their knees to their chests. Well that knee to chest stretch might loosen some tight muscles but that’s spine flexion and spine flexion is the principle cause of vertebral disc bulges, herniations and CAUSES tight muscles. Following up the knee to chest stretch with a bunch of rotation stretching bringing the knees side to side and physical therapy absolutely can make you worse.
With acute back pain, the hippocratic oath seems a good place to start, “First do no harm.” Stretches and aggressive exercises are likely going to worsen the patient, however light motor control exercises which place minimal stress on the spine and teaching patients to keep the spine neutral, bend at their hips, and use good lumbar support when sitting will go a long way towards allowing the spine to heal. Later more aggressive core, hip and leg exercises can begin. Electric muscle stimulation actually does do a good job at lessening pain via gate control theory and helps strengthen core muscles, and my patients frequently report it lessens the feeling of muscle spasms as well, but I’ll have to look the latter up to see if there is any evidence to support that. [edit to add, it does]
The abstract conclusion above makes the paper sound as if results are preliminary. In the paper itself, the authors (the principle is a chiropractor who uses manipulation in his daily practice) are more blunt:
“At least one lesson should be drawn from this review, continuing in the same vein seems pointless. After all, there are currently more than 100 RTTS of SMT for low back pain (Rubinstein 2012). Despite the disappointing quality of the evidence examined here, a more precise estimate of the effect of SMT for acute low-back pain, a condition with a rather benign natural history, does not appear to be the way forward. Preventing the onset of chronic low-back pain, which is disabling and expensive may be a much more clinically relevant question.”
All I can say is, “here here,” however there has been a good bit of research over the last couple decades that helps answer that question. The best answer being to teach patients with acute back pain to avoid what probably caused their acute pain in the first place. That generally being to avoid repeated or sustained spine motions in extension, twisting and most frequently flexion. Don’t slouch, set up chairs with adequate lumbar support to avoid sustained spine flexion. Exercise to be fit enough to do the former without fatigue, preferably using exercises that teach good motor control, and avoid said aggravating spine motions. How does manipulation/mobilization help with any of that? It doesn’t.
Thanks for reading my blog. If you have any questions or comments (even hostile ones) please don’t hesitate to ask/share. If you’re reading one of my older blogs, perhaps unrelated to neck or back pain, and it helps you, please remember Spinal Flow Yoga for you or someone you know in the future.
Chad Reilly is a Physical Therapist, obtaining his Master’s in Physical Therapy from Northern Arizona University. He graduated Summa Cum Laude with a B.S. Exercise Science also from NAU. He is a Certified Strength and Conditioning Specialist, and holds a USA Weightlifting Club Coach Certification as well as a NASM Personal Training Certificate. Chad completed his Yoga Teacher Training at Sampoorna Yoga in Goa, India.