My Facebook feed was recently flooded with multiple shares of a summary of massage therapy research findings for various health problems from the Association of Massage Therapists (AMT). Because of my interest in musculoskeletal pain and dealing with clients having such pains regularly, I took a closer look at the studies cited for neck and shoulder pain.
Among the systematic reviews and meta-analyses cited, two of them are Chinese reviews, one Canadian, and one Cochrane Review, which was authored by American and Canadian researchers. While three of the reviews find massage therapy to have short-term pain relief effects and one review found “moderate evidence” of massage therapy on decreasing neck pain — stated on AMT’s summary — there is more to the story that made me question the strength of the evidence.
While all of the reviews found that massage therapy has immediate pain relief and any long-term benefits is unknown, there are a few problems the authors encountered.
Massage Definition Is Too Broad
In the review by Kong et al., the authors identified many types of massage therapy among 12 eligible studies reviewed: Swedish, Chinese massage, Thai massage, slow-stroke back massage, manual pressure release, and myofascial band therapy.(1) Likewise, the Cochrane Review addressed a similar problem, “e.g. Traditional Chinese massage, ischaemic compression, self-administered ischaemic pressure using a J-knob cane, conventional Western massage and occipital release.”(2)
The Ottawa review stated, “It was difficult to determine the effects of type and dosage of massage because the RCTs employed different techniques, durations, and treatment protocols. Most studies of massage therapy combined various techniques, which were likely applied differently by each therapist.”(3) The problem is that we don’t know for sure which type of massage is more or less beneficial than another type of massage for treating neck pain. Do I need to do kneading, skin stretching, Thai massage? Should I use the J-knob cane? Because we cannot readily identify what works better, we need to be careful when deciding what technique to use — not because it’s our favorite modality, but because the client or patient perceives it as beneficial.
Massage Is No Better Than Most “Active Therapies”
When compared to other types of treatments, massage isn’t better — or worse. Among 13 eligible randomized-controlled trials, Cheng and Huang found that “Although [massage therapy] did not show significant immediate effects on pain relief compared with active therapies, [massage] showed superior immediate effects on pain relief versus traditional Chinese medicine.”(4) However, they reported that it is no better than traction (n=3) and acupuncture (n=2) and other manual therapies (n=2) had better pain relief than massage.
Kong et al. and the Ottawa review found similar results.(1,3) The former concluded that massage therapy “does not show better effects than other active therapies on pain relief.” There was no evidence indicating that massage was effective in improving functional status of neck and shoulder pain.
The Cochrane Review, however, is more critical — as it should be with Cochrane Reviews. The authors stated, “There is no difference in pain intensity, physical function and quality of life when massage is compared with other therapies such as manual therapy, acupuncture, education, exercise and multimodal intervention. However, studies that compare one active treatment versus another active treatment require larger sample sizes than studies that compare an active treatment with a placebo. Thus, it is impossible to determine whether the ‘no difference’ findings in the studies comparing active treatment with active treatment reflect true equivalence or merely sample sizes too small to detect a difference.”(4)
The Review also found no differences when different massage therapy techniques were compared among each other. They also added this little gem: “Even when statistical significance was found, such as an improvement in pain with the combination of ischaemic compression and passive stretch compared with individual treatment, the lack of replicability of the study precludes making a statement about the effectiveness of one massage technique over another.”(4)
In other words, we should not make broad statements saying that one type of massage is better than another type of massage or treatment. And we should take these results with the likely possibility that they could be wrong should better evidence disconfirm these findings, which is something we should all consider when reading and interpreting research.
Massage Therapy Is Better Than Inactive Therapies
But that’s great news, isn’t it? Umm…not really. Patients who receive massage therapy obviously feel better than those receiving “standard” medical care or are on the wait-list. This was reported in all four reviews.
There are two problems with this thinking:
First, having some degree of socialization will elicit some change of pain perception, often for the better. So someone in pain who is interacting with another person will likely have a greater reduction in pain than those who receive no or minimum care. For example, a randomized sham-control study of Reiki found that cancer patients with who were treated by a real Reiki Master had no better outcome than those treated by an actor pretending to be a Reiki Master, who simply mimicked the moves. However, both groups reported to feel better and have less pain than those receiving standard care. The authors concluded, “The findings indicate that the presence of [a registered nurse] providing one-on-one support during chemotherapy was influential in raising comfort and well-being levels, with or without an attempted healing energy field.” (5)
Another study in acupuncture also found similar results where real acupuncture was no better than fake acupuncture in alleviating knee pain for patients with osteoarthritis, but these two groups had better pain relief than those receiving standard care.(6)
The second problem is that we don’t know how well the trials were blinded in the reviews. Control groups that are not blinded during the selection may likely experience higher levels of pain, knowing that they aren’t receiving a massage or another type of care. Cheng and Huang reported, “There were serious flaws in blinding methods of most Chinese RCTs. It is difficult to blind the patients and impossible to blind the therapists, but blinded assessors and concealed allocation must attempt to make up for the lack of blinding. However, some Chinese RCTs did not perform these compensated methods. Thus, these studies could not be considered to be of high quality.”(4)
Small Sample Fallacy
Few of the selected studies had more than 100 subjects, which makes these studies to be more prone to the small sample fallacy. Smaller samples increases the odds of getting a false positive or a false negative because the samples do not accurately reflect on the actual population examined.(7) They can also over-estimate an association between two or more variables and may not reflect on the true effect due to their low statistical power.(8,9) Publication bias, selective data analysis, and selective reporting of outcomes are more likely to affect such studies, as well as poor experimental setup. Therefore, systematic reviews are only as good as the quality of the trials examined.
On publication bias, Buttons et al reported, “A ‘negative’ result in a high-powered study cannot be explained away as being due to low power, and thus reviewers and editors may be more willing to publish it, whereas they more easily reject a small ‘negative’ study as being inconclusive or uninformative. The protocols of large studies are also more likely to have been registered or otherwise made publicly available, so that deviations in the analysis plans and choice of outcomes may become obvious more easily. Small studies, conversely, are often subject to a higher level of exploration of their results and selective reporting thereof.”(9)
Philosophy professor Kevin DeLaplante of the Critical Thinking Academy gave a few examples of how the small sample fallacy in research could misinform national policies and cost us billions of dollars.
The Good News
Given the examination of the evidence on neck and shoulder pain, I wonder what other things the AMT’s summary of massage research isn’t telling us. If we read the full research papers, would we find similar problems for low back pain and pain relief of cancer patients?
While there are problems with current massage research, such as low-quality of evidence, this does not mean that we should not perform massage therapy for those suffering from neck and shoulder pain. What we should consider are the limitations of what massage can do and what we may say to our patients or clients. Short-term pain relief may provide patients and clients a positive mood change, which may decrease their sensitivity in their nervous system or their catastrophication of pain.
It may help them sleep better, encourage them to move more, and give them optimism that they do not have to live with pain for life. They should be well-informed about what massage therapy can do and cannot do for them, just as we massage professions should be informed about what the massage research really says.
- Kong LJ, Zhan HS, Cheng YW, Yuan WA, Chen B, Fang M. Massage Therapy for Neck and Shoulder Pain: A Systematic Review and Meta-Analysis. Evidence-based Complementary and Alternative Medicine : eCAM. 2013;2013:613279. doi:10.1155/2013/613279.
- Patel KC, Gross A, Graham N, Goldsmith CH, Ezzo J, Morien A, Peloso PMJ. Massage for mechanical neck disorders. Cochrane Database of Systematic Reviews 2012, Issue 9. Art. No.: CD004871. DOI: 10.1002/14651858.CD004871.pub4
- Cheng YH, Huang GC. Efficacy of Massage Therapy on Pain and Dysfunction in Patients with Neck Pain: A Systematic Review and Meta-Analysis. Evidence-based Complementary and Alternative Medicine : eCAM. 2014;2014:204360. doi:10.1155/2014/204360.
- Brosseau L et al. Ottawa Panel evidence-based clinical practice guidelines on therapeutic massage for neck pain. J Bodyw Mov Ther. 2012 Jul;16(3):300-25. doi: 10.1016/j.jbmt.2012.04.001. Epub 2012 May 9.
- Catlin A, Taylor-Ford RL. Investigation of standard care versus sham Reiki placebo versus actual Reiki therapy to enhance comfort and well-being in a chemotherapy infusion center. Oncol Nurs Forum. 2011 May;38(3):E212-20. doi: 10.1188/11.ONF.E212-E220.
- Suarez-Almazor ME1, Looney C, Liu Y, Cox V, Pietz K, Marcus DM, Street RL Jr. A randomized controlled trial of acupuncture for osteoarthritis of the knee: effects of patient-provider communication. Arthritis Care Res (Hoboken).2010 Sep;62(9):1229-36. doi: 10.1002/acr.20225.
- Kalla S. Statistical Significance And Sample Size. Explorable.
- Hackshaw A. Small studies: strengths and limitations. European Respiratory Journal. 2008 Nov; 32 (5) 1141-1143.doi: 10.1183/09031936.00136408.
- Button KS et al. Power failure: why small sample size undermines the reliability of neuroscience. Nature Reviews Neuroscience 14, 365-376 (May 2013) | doi:10.1038/nrn3475.
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