The greatest hits of back pain science are a disappointment
Thirteen pages on PainSci cite Machado 2009: 1. Deep Friction Massage Therapy for Tendinitis 2. The Complete Guide to Low Back Pain 3. Are Orthotics Worth It? 4. Microbreaking 5. Healer Syndrome 6. Does Spinal Manipulation Work? 7. Pseudo-Quackery in Physical Therapy 8. Science versus Experience in Musculoskeletal Medicine 9. “Windows of Opportunity” in Rehab 10. The greatest hits of back pain science 11. Major good news study for back pain (which validates my career) 12. Massage for back pain: an interesting scientific flip-flop 13. Walking back the WalkBack Trial
PainSci commentary on Machado 2009: ?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided wherever possible.
This is a meticulous, sensible, and readable analysis of the very best studies of back pain treatments that have ever been done: the greatest hits of back pain science. There is a great deal of back pain science to review, but authors Machado, Kamper, Herbert, Maher and McCauley found that shockingly little of it was worth their while: just 34 acceptable studies out of a 1031 candidates, and even among those “trial quality was highly variable.” Their conclusions are derived from only the best sort of scientific experiments: not just the gold-standard of randomized and placebo-controlled tests, but carefully choosing only the “right” kind of placebos (several kinds of placebos were grounds for disqualification, because of their known potential to skew the results). They do a good job of explaining exactly how and why they picked the studies they did, and pre-emptively defending it from a couple common concerns. The results were sad and predictable, robust evidence of absence: “The average effects of treatments … are not much greater than those of placebos.”
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
OBJECTIVE: Estimates of treatment effects reported in placebo-controlled randomized trials are less subject to bias than those estimates provided by other study designs. The objective of this meta-analysis was to estimate the analgesic effects of treatments for non-specific low back pain reported in placebo-controlled randomized trials.
METHODS: Medline, Embase, Cinahl, PsychInfo and Cochrane Central Register of Controlled Trials databases were searched for eligible trials from earliest records to November 2006. Continuous pain outcomes were converted to a common 0-100 scale and pooled using a random effects model.
RESULTS: A total of 76 trials reporting on 34 treatments were included. Fifty percent of the investigated treatments had statistically significant effects, but for most the effects were small or moderate: 47% had point estimates of effects of <10 points on the 100-point scale, 38% had point estimates from 10 to 20 points and 15% had point estimates of>20 points. Treatments reported to have large effects >20 points) had been investigated only in a single trial.
CONCLUSIONS: This meta-analysis revealed that the analgesic effects of many treatments for non-specific low back pain are small and that they do not differ in populations with acute or chronic symptoms.
related content
- “Systematic review of manual therapies for nonspecific neck pain,” Vincent et al, Joint Bone Spine, 2013.
- “More questions than answers,” Davis, Physical Therapy, 2002.
- “A systematic review reveals that the credibility of subgroup claims in low back pain trials was low,” Saragiotto et al, J Clin Epidemiol, 2016.
- “Subgrouping Patients With Nonspecific Low Back Pain: Hope or Hype?,” Saragiotto et al, Journal of Orthopaedic & Sports Physical Therapy, 2017.
- “Low back pain symptoms show a similar pattern of improvement following a wide range of primary care treatments: a systematic review of randomized clinical trials,” Artus et al, Rheumatology (Oxford), 2010.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Classical Conditioning Fails to Elicit Allodynia in an Experimental Study with Healthy Humans. Madden 2017 Pain Med.
- Topical glyceryl trinitrate (GTN) and eccentric exercises in the treatment of mid-portion achilles tendinopathy (the NEAT trial): a randomised double-blind placebo-controlled trial. Kirwan 2024 Br J Sports Med.
- Placebo analgesia in physical and psychological interventions: Systematic review and meta-analysis of three-armed trials. Hohenschurz-Schmidt 2024 Eur J Pain.
- Recovery trajectories in common musculoskeletal complaints by diagnosis contra prognostic phenotypes. Aasdahl 2021 BMC Musculoskelet Disord.
- Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. Moore 2023 J Pain.