An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle
Three articles on PainSci cite Shah 2005: 1. The Complete Guide to Trigger Points & Myofascial Pain 2. Toxic Muscle Knots 3. The Trigger Point Identity Crisis
PainSci notes on Shah 2005:
This is an important research attempt to analyze the tissue chemistry of myofascial trigger points. For details and analysis, however, see the improved 2008 follow-up study (Shah), Dr. David Simons’ summary (Simons), and my own article, Toxic Muscle Knots.
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.
Myofascial pain associated with myofascial trigger points (MTrPs) is a common cause of nonarticular musculoskeletal pain. Although the presence of MTrPs can be determined by soft tissue palpation, little is known about the mechanisms and biochemical milieu associated with persistent muscle pain. A microanalytical system was developed to measure the in vivo biochemical milieu of muscle in near real time at the subnanogram level of concentration. The system includes a microdialysis needle capable of continuously collecting extremely small samples (approximately 0.5 microl) of physiological saline after exposure to the internal tissue milieu across a 105-microm-thick semi-permeable membrane. This membrane is positioned 200 microm from the tip of the needle and permits solutes of <75 kDa to diffuse across it. Three subjects were selected from each of three groups (total 9 subjects): normal (no neck pain, no MTrP); latent (no neck pain, MTrP present); active (neck pain, MTrP present). The microdialysis needle was inserted in a standardized location in the upper trapezius muscle. Due to the extremely small sample size collected by the microdialysis system, an established microanalytical laboratory, employing immunoaffinity capillary electrophoresis and capillary electrochromatography, performed analysis of selected analytes. Concentrations of protons, bradykinin, calcitonin gene-related peptide, substance P, tumor necrosis factor-alpha, interleukin-1beta, serotonin, and norepinephrine were found to be significantly higher in the active group than either of the other two groups (P < 0.01). pH was significantly lower in the active group than the other two groups (P < 0.03). In conclusion, the described microanalytical technique enables continuous sampling of extremely small quantities of substances directly from soft tissue, with minimal system perturbation and without harmful effects on subjects. The measured levels of analytes can be used to distinguish clinically distinct groups.
related content
- “Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points,” Shah et al, Archives of Physical Medicine & Rehabilitation, 2008.
- “Uncovering the biochemical milieu of myofascial trigger points using in vivo microdialysis: an application of muscle pain concepts to myofascial pain syndrome,” Shah et al, Journal of Bodywork & Movement Therapies, 2008.
- Toxic Muscle Knots — Research suggests myofascial trigger points may be quagmires of irritating molecules
- “New Views of Myofascial Trigger Points: Etiology and Diagnosis,” Simons, Archives of Physical Medicine & Rehabilitation, 2008.
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:
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