ABSTRACT This issue’s column summaries an influential sequence of publications in which Helene Langevin and her colleagues reported their findings from carefully conducted experiments with laboratory animals – that stretching connective tissues could have anti-inflammatory and anti-fibrotic effects, and could even reduce pain sensitivity. This suggests, but does not conclusively prove, that stretching fascia in humans might confer similar benefits.
To begin our new feature, brief reviews of fascia research, we will look at a very influential series of studies by one of the leading scientists in this field, Helene Langevin, and her associates. In these experiments they found that stretching experimentally compromised connective tissue in mice and rats reduced inflammation, fibrosis, and pain sensitivity, and they also elucidated several underlying mechanisms. This group’s publications exemplify the highest standards of this type of animal research. If you follow the links in the references at the end you can view the original articles, some of which are rich in graphics, and learn about the detail and care that go into the best research of this kind.
In a widely noted 2007 study, Langevin combined ultrasound movies of soft-tissue movement – elastography – with histological staining and a novel application of image processing to confirm her earlier findings that the rotation of acupuncture needles in human soft tissue, which is a common therapeutic technique in traditional Chinese medicine, causes collagen fibers to wind around the needle and radiate a stretch through the surrounding fascia that extended up to ten centimeters from the needle (Langevin et al. 2007). Considered together with findings that acupuncture reduces pain in mice by causing the release of adenosine and related compounds which reduce the pain sensitivity of neurons (Goldman et al. 2010, Takano et al. 2012), this suggested that their release might be caused by the mechanical force radiating through connective tissue from the acupuncture needle, particularly through intermuscular connective-tissue planes that often correlate with the location of traditional acupuncture meridians. A second, simultaneous mechanism for longer term pain reduction might be an increase of fascial glide along such planes (Langevin 2014).
Turning to the investigation of the effects of unidirectional rather than radial stretching of soft tissues, Langevin’s group found that that two types of immune cells known to promote scarring and fibrosis in connective tissue – transforming growth factor beta I, and type I procollagen – were both reduced in experimentally micro-injured mouse tissue following seven days of stretching that was brief (ten minutes) and moderate (20%-30% strain)(Bouffard et al. 2008).
A subsequent investigation found that stretching inflamed low-back tissue in rats for ten minutes twice a day for twelve days reduced inflammation, restored stride length and intra-step distance, and decreased pain sensitivity. The expression of another type of cells that proliferate in inflamed tissue – macrophages – was also reduced (Corey et al. 2012).
An even more fundamental mechanism for these anti-inflammatory effects, one that might underlie the decreases in pro-inflammatory cell types found in the earlier studies, was demonstrated by stretching experimentally inflamed back tissue of rats for ten minutes at ~25% strain twice daily for two days. This produced an increase in the concentration of a class of molecules known to promote the resolution of inflammation – resolvins – and a consequent reduction in the thickness of inflamed tissue and decreased concentration of neutrophils – white blood cells that accumulate at sites of injury (Berrueta et al. 2016).
Another study examined the effects of soft-tissue stretching in rats with experimentally induced sclerodermatosis, a condition that has features in common with systemic sclerosis, an autoimmune disease that also occurs in humans causing fibrosis of the skin and subcutaneous tissue, leading to adhesions and impaired movement. White blood cells from rats genetically predisposed to sclerosis were injected into non-predisposed rats resulting in skin inflammation followed by fibrosis. Stretching for ten minutes daily after three weeks reduced skin thickness, and increased the glide between skin and subcutaneous tissues. Mechanistically, reductions were found after four weeks in the expression in the skin of two genes known to be active in mouse and one form of human scleroderma – CCL2 and ADAM8. However, inflammation was not reduced when it peaked at week two (Xiong et al. 2017).
This sequence of experiments as a whole suggests the possibility that mild, brief, repeated stretching of fascia mightproduce comparable anti-inflammatory and anti- fibrotic effects, and even pain reduction in humans. But that generalization cannot be confirmed on the basis of these studies alone, because effects found in animal studies are not always found nor found in exactly the same way in humans. The same benefits might require different durations, magnitudes and/or frequencies of stretching in human subjects, and underlying mechanisms might also differ because the human immune system does not function in exactly the same way as those of laboratory animals. However, if comparable effects and mechanisms were to be found in humans, then they might apply to the effects of manual therapies that stretch connective tissue such as Rolfing® Structural Integration. In a later column we will look at studies of the effects of stretching connective tissue in humans.
Eric Jacobson, PhD, MPH was trained by Ida Rolf in 1974 and completed advanced Rolfing training with the Rolf Institute® in 2005. He has a private practice of Rolfing Structural Integration in Boston. He also teaches medical anthropology and investigates alternative medicines at Harvard Medical School. In 2009 he completed an NIH-funded, randomized clinical trial of structural integration for chronic low back pain; the study is available at https:// www.ncbi.nlm.nih.gov/pmc/articles/ PMC4405211/pdf/ECAM2015-813418.
Eric can be contacted by email at eric_ [email protected].
Berrueta, L, I. Muskaj, S. Olenich, T. Butler, G.J. Badger, R.A. Colas, M. Spite,
C.N. Serhad, and H.M. Langevin 2016 Jul. “Stretching Impacts Inflammation Resolution in Connective Tissues.” Journal of Cellular Physiology 231(7):1621–27. Available at https://www.ncbi.nlm.nih. gov/pmc/articles/PMC5222602/pdf/ nihms836638 (retrieved 2/24/19).
Bouffard, N., K.R. Cutroneo, G.J. Badger,
S.L. White, T.R. Buttolph, H.P Ehrlich, D. Stevens-Tuttle, and H.M. Langevin 2008
Feb. “Tissue Stretch Decreases Soluble TGF-beta1 and Type1 Procollagen in Mouse Subcutaneous Connective Tissue.” Journal of Cellular Physiology 214(2):389–395. Available at https:// www.ncbi.nlm.nih.gov/pmc/articles/ PMC3065715 (retrieved 2/24/19).
Corey, S.M., et al. 2012 Jan. “Stretching of the Back Improves Gait, Mechanical Sensitivity and Connective Tissue Inflammation in a Rodent Model.” PLoS One 7(1):e29831. Available at https://www.ncbi. nlm.nih.gov/pmc/articles/PMC3253101/ pdf/pone.0029831 (retrieved 2/24/19).
Goldman, N, M. Chen, T. Fujita, Q. Xu,
Langevin, H.M., D.M. Rizzo, J.R. Fox,
G.J. Badger, J. Wu, E.E. Konofagou, D. Stevens-Tuttle, N.A. Bouffard, and M.H. Krag 2007. “Dynamic Morphometric Characterization of Local Connective Tissue Network Structure in Humans Using Ultrasound.” BMC Systems Biology 2007 1:25. Available at www. biomedcentral.com/1752-0509/1/25 (retrieved 2/24/19).
Langevin, H. 2014. “Acupuncture, Connective Tissue, and Peripheral Sensory Modulation.” Critical Reviews in Eukaryotic Gene Expression 24(3):249–253.
Takano, T, X. Chen, F. Luo, T. Fujita, Z. Ren, N. Goldman, Y. Zhao, J.D. Markman, and M. Nedergaard 2012. “Traditional Acupuncture Triggers a Local Increase in Adenosine in Human Subjects.” The Journal of Pain 13(12):1215–23. Available at https://www.ncbi.nlm.nih.gov/pmc/ articles/PMC3587733/pdf/nihms-413306 (retrieved 2/24/19).
Xiong Y., L. Berrueta, K. Urso, S. Olenich,