• Good advice for aches, pains & injuries
bibliography*The PainScience Bibliography contains plain language summaries of thousands of scientific papers and others sources, like a specialized blog. This page is about a single scientific paper in the bibliography, Morikawa 2017.

Compression at Myofascial Trigger Point on Chronic Neck Pain Provides Pain Relief through the Prefrontal Cortex and Autonomic Nervous System: A Pilot Study


Tags: treatment, odd, self-treatment, massage, etiology, muscle pain, neck, manual therapy, pro, muscle, pain problems, head/neck, spine

PainSci summary of Morikawa 2017?This page is one of thousands in the 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 at the bottom of the page, as often as possible. ★★★☆☆?3-star ratings are for typical studies with no more (or less) than the usual common problems. Ratings are a highly subjective opinion, and subject to revision at any time. If you think this paper has been incorrectly rated, please let me know.

This is a tiny test of treating trigger points with thumb pressure in just 10 patients with chronic neck pain. Their pain was modestly reduced compared to 10 control patients, and they had increased parasympathetic nervous system activity (relaxation, in other words, measured with brain blood flow and heart rate variability). They were testing the daring but dubious hypothesis that

compression at MTrPs induces pain relief through inhibition of sympathetic activity, which (1) might increase the peripheral blood flow and subsequent removal of noxious substances, and (2) might block the excessive release of acetylcholine.

There’s a lot wrong with that, but whatever: the study isn’t designed to show causation, and their idea is implausible on its face because relaxation usually does not put a dent in trigger point pain. Probably all this study does is confirm (in a highly technical way) the common sense observation that “pain relief is relaxing.” Or just that pushing on sore neck muscles is relaxing. Which is actually worth knowing, maybe.

See the trigger points tutorial for a more detailed analysis.

original abstractAbstracts 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.

Compression at myofascial trigger points (MTrPs), known as "ischemic compression," has been reported to provide immediate relief of musculoskeletal pain and reduce the sympathetic activity that exacerbates chronic pain. We conducted a pilot study to investigate the possible involvement of the prefrontal cortex in pain relief obtained by MTrP compression in the present study, and analyzed the relationships among prefrontal hemodynamic activity, activity of the autonomic nervous system, and subjective pain in patients with chronic neck pain, with and without MTrP compression. Twenty-one female subjects with chronic neck pain were randomly assigned to two groups: MTrP compression (n = 11) or Non-MTrP compression (n = 10). Compression for 30 s was conducted 4 times. During the experiment, prefrontal hemodynamic activity [changes in Oxy-hemoglobin (Hb), Deoxy-Hb, and Total-Hb concentrations] and autonomic activity based on heart rate variability (HRV) were monitored by using near infrared spectroscopy (NIRS) and electrocardiography (ECG), respectively. The results indicated that MTrP compression significantly reduced subjective pain compared with Non-MTrP compression. The spectral frequency-domain analyses of HRV indicated that a low frequency (LF) component of HRV was decreased, and a high frequency (HF) component of HRV was increased during MTrP compression, while LF/HF ratio was decreased during MTrP compression. In addition, prefrontal hemodynamic activity was significantly decreased during MTrP compression compared with Non-MTrP compression. Furthermore, changes in autonomic activity were significantly correlated with changes in subjective pain and prefrontal hemodynamic activity. Along with previous studies indicating a role for sympathetic activity in the exacerbation of chronic pain, the present results suggest that MTrP compression in the neck region alters the activity of the autonomic nervous system via the prefrontal cortex to reduce subjective pain.

related content

These three articles on cite Morikawa 2017 as a source:

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: