• 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, Weppler 2010.

Flexibility gains due to changes in sensation, not muscle length


Tags: stretch, biology, exercise, self-treatment, treatment, muscle

PainSci summary of Weppler 2010?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. ★★★★☆?4-star ratings are for bigger/better studies and reviews published in more prestigious journals, with only quibbles. 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.

People seem to be more flexible when they stretch regularly for a while, but why? A number of explanations have been proposed, and none have panned out. This article reviews them all in great detail, and the full text is free. It’s not light reading, but there are some fascinating highlights.

For instance, the popular theory that muscles actually change length (“plastic deformation”) is dismissed: “In 10 studies that suggested plastic, permanent, or lasting deformation of connective tissue as a factor for increased muscle extensibility, none of the cited evidence was found to support this classic model of plastic deformation.” After reviewing several more disproven popular theories, the authors conclude:

Increases in muscle extensibility observed immediately after stretching and after short-term (3 to 8-week) stretching programs are due to an alteration of sensation only and not to an increase in muscle length. This theory is referred to as the sensory theory throughout this article because the change in subjects’ perception of sensation is the only current explanation for these results.

In short, elongation is normally limited by strict neurological edict, in much the way that we have much greater muscle power available than we can normally, safely use. But to some extent we get used to stretching — we can learn to tolerate greater elongation.

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.

Various theories have been proposed to explain increases in muscle extensibility observed after intermittent stretching. Most of these theories advocate a mechanical increase in length of the stretched muscle. More recently, a sensory theory has been proposed suggesting instead that increases in muscle extensibility are due to a modification of sensation only. Studies that evaluated the biomechanical effect of stretching showed that muscle length does increase during stretch application due to the viscoelastic properties of muscle. However, this length increase is transient, its magnitude and duration being dependent upon the duration and type of stretching applied. Most of these studies suggest that increases in muscle extensibility observed after a single stretching session and after short-term (3- to 8-week) stretching programs are due to modified sensation. The biomechanical effects of long-term >8 weeks) and chronic stretching programs have not yet been evaluated. The purposes of this article are to review each of these proposed theories and to discuss the implications for research and clinical practice.

related content

These four articles on cite Weppler 2010 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: