PainSci commentary on Sohns 2016: ?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 an extremely tiny German study of just a dozen (!) patients with shoulder pain, comparing “compression therapy” with “manual sham therapy.” This is such a small sample size that it scarcely matters what the results were: they can’t be taken seriously on their own, or even really contribute much to the anemic literature. One wonders why they even bothered. Hey, science: do it right or don’t bother!
For what little it’s worth, both groups improved, and there was no statistically significant difference between them for the primary outcomes, and that is a negative result. But of course they tried to find some good news, and they report that compression was slightly more successful “by different parameters”: translation, the main outcomes weren’t good enough for a positive conclusion, but if you measure enough other stuff you can usually find something that looks like good news.
One thing that stands out in this study was that they designed it to “detect a potential … hyperalgesia,” a more all-over sensitivity and not just at trigger points, which is open-minded of them (not the blinkered view of trigger point pathophysiology that is the inspiration and foundation for most similar research). And based on that, they make one noteworthy point: “The significant improvement of pressure-pain-threshold values in the interventional group even at sites that were not directly treated, indicates central mechanisms in pain threshold modulation induced by manual compression therapy.” Indeed it does indicate that, insofar as we can trust such a tiny pool of data.
~ Paul Ingraham
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.
BACKGROUND: Although chronic shoulder pain is highly prevalent and myofascial trigger points (mTrP) are thought to be found in the majority of patients with shoulder complaints, the influence on the pain mechanism remains unclear. There are only very few controlled clinical studies on the effects of manual trigger point compression therapy.
OBJECTIVE: This randomized controlled trial (RCT) compared the short-term effects of manual trigger point compression therapy (n = 6) «Six?! Is that a joke?» with manual sham therapy (n = 6) in patients with unilateral shoulder pain due to myofascial syndrome (MFS).
MATERIAL AND METHODS: The measurement data were collected before and after two sessions of therapy. Pressure pain thresholds (PPT) of mTrP and symmetrically located points on the asymptomatic side were measured together with neutral points in order to detect a potential unilateral or generalized hyperalgesia. Additionally, the pain was assessed on a visual analog scale (VAS) at rest and during movement and the neck disability index (NDI) and disabilities of the arm, shoulder and hand (DASH) questionnaires were also completed and evaluated.
RESULTS: Both treatment modalities led to a significant «and roughly equal» improvement; however, the manual trigger point compression therapy was significantly more effective in comparison to sham therapy, as measured by different parameters «secondary outcomes, not primary».
CONCLUSION: The significant improvement of PPT values in the interventional group even at sites that were not directly treated, indicates central mechanisms in pain threshold modulation induced by manual compression therapy. The weaker but still measurable effects of sham therapy might be explained by the sham modality being a hands on technique «Ya think?!» or by sufficient stimulation of the trigger point region during the diagnostics and PPT measurements.
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:
- Exercise and education versus saline injections for knee osteoarthritis: a randomised controlled equivalence trial. Bandak 2022 Ann Rheum Dis.
- Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-based Cohort Study. Kasch 2022 Spine (Phila Pa 1976).
- A double-blinded randomised controlled study of the value of sequential intravenous and oral magnesium therapy in patients with chronic low back pain with a neuropathic component. Yousef 2013 Anaesthesia.
- Is Neck Posture Subgroup in Late Adolescence a Risk Factor for Persistent Neck Pain in Young Adults? A Prospective Study. Richards 2021 Phys Ther.
- Sudden amnesia resulting in pain relief: the relationship between memory and pain. Choi 2007 Pain.