PainSci summary of Heinemeier 2018: ?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 at the bottom of the page, as often as possible.
An earlier study from the same researchers used a rather sensational method to demonstrate that Achilles tendon tissue is forever: what we create when we are young is still there decades later. They know this because they found contamination from nuclear bomb tests, trapped in tendon tissue like a fly in amber.
But those subjects were all healthy. In this follow-up study, they looked at both healthy and unhealthy tendons … and found a surprise.
Un-healthy tendon does get recycled. •mind blown•
This is a hard result to interpret, but the authors take a stab at it. They propose that it means one of two things:
- Tendon disease causes tendons to start recycling and regenerating tissue, trying to cope with the load. And then, much later, symptoms.
- Tendon turnover is actually a cause of tendinopathy. For unknown reasons, the tendon is trying to rebuild itself, and becomes unhealthy as a result.
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.
Tendons are essential weight-bearing structures that are often affected by tendinopathy, which leads to pain and impaired mobility. In healthy Achilles tendons, no significant renewal of the weight-bearing collagen matrix seems to occur during adult life, but tendinopathy may lead to increased turnover. The carbon-14 ([14C]) bomb pulse method was used to measure lifelong replacement rates of collagen in tendinopathic and healthy Achilles tendons (tendinopathic: n = 25, born 1937-1972. Healthy: n = 10, born 1929-1966). As expected, the healthy tendon collagen had not been replaced during adulthood, but in tendinopathic tendon, a substantial renewal had occurred. Modeling of the [14C] data suggested that one half of the collagen in tendinopathic matrix had undergone continuous slow turnover for years before the presentation of symptoms. This finding allows for a new concept in tendon pathogenesis because it suggests that either the symptoms of tendinopathy represent a late phase of a very prolonged disease process, or an abnormally high collagen exchange could be a risk factor for tendon disorders rather than being a result of disease.
- “In vivo investigation of tendon responses to mechanical loading,” K M Heinemeier and M Kjaer, J Musculoskelet Neuronal Interact, 2011.
- “Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb (14)C,” Katja Maria Heinemeier, Peter Schjerling, Jan Heinemeier, Stig Peter Magnusson, and Michael Kjaer, FASEB J, 2013.
- “Effects of anti-inflammatory (NSAID) treatment on human tendinopathic tissue,” Katja Maria Heinemeier, Tommy F Øhlenschlæger, Ulla Ramer Mikkelsen, Freja Sønder, Peter Schjerling, Rene B Svensson, and Michael Kjaer, J Appl Physiol (1985), 2017.
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:
- Modulation in the elastic properties of gastrocnemius muscle heads in individuals with plantar fasciitis and its relationship with pain. Zhou 2020 Sci Rep.
- Association Between Plantar Fasciitis and Isolated Gastrocnemius Tightness. Nakale 2018 Foot Ankle Int.
- Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial. Munteanu 2015 Br J Sports Med.
- A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power. Gronau 2017 Comprehensive Results in Social Psychology.
- The neck and headaches. Bogduk 2014 Neurol Clin.