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I've been training my entire life for this moment.
Achilles tendon ruptures start as isolated tendon injuries but quickly become complex muscle-tendon pathologies... \\1 https://twitter.com/wojespn/status/1329492642896470016
Achilles tendon ruptures start as isolated tendon injuries but quickly become complex muscle-tendon pathologies... \\1 https://twitter.com/wojespn/status/1329492642896470016
we need to appreciate the huge loads that these tendons experience... 10x bodyweight during sport activity... that is like 2 grand pianos or 1/2 rhinoceros. I'm always amazed by how infrequently (although still to common) people rupture their Achilles tendon. \\2
I don't have inside info but @KlayThompson will undergo surgery to repair rupture. this is done 1 of 2 ways - big exposing the tendon and tying lots of knots or small incision and using a guide to pass suture thru tendon before tying lots of knots... either way - merit badge! \\2
after this surgery - his ankle will be flexed and placed in a protective cast or boot to offload the healing tendon. so far so good. but problem is that the calf muscles that pull on the Achilles tendon don't like that! they respond by remodeling. \\3
and these muscles remodel by getting rid of their functional units (sarcomeres) in series. as the muscle gets shorter, it stretches the healing tendon. this stretch can even damage the healing tendon even though the patient never touches their foot to the ground. /4
to mitigate these bad effects of prolonged unloading - he'll start to walk around after a few weeks to begin loading the tendon to promote healing. but be careful! the surgical repair can only withstand ~0.5 bodyweights but walking can exceed 2+ bodyweights. /5
even when walking in an immobilizing boot - the tendon still experiences loads that exceed the strength of the surgical repair. So the real trick is to increase tendon loads a tad behind the healing strength of the tendon. /6
when the tendon gets longer and the muscle gets shorter - the calf muscles do less work, especially in more ankle extension (like when you jump or sprint). We found that more muscle remodeling = more function deficits during high-speed contractions. /7
my group in the @pennmotionlab - @BiomechHullfish developed a simple way to continuously monitor Achilles tendon load while walking in one of those chunky plastic boots. /8 http://www.sciencedirect.com/science/article/pii/S0021929020303481
with the support from @AOFAS we are beginning to measure tendon loading in patients while they walk around our lab. We hope to extend this outside of the lab to monitor patients and identify what loads are the best loads. /9
Beyond elites. Ruptures are a major clinical prob. 2/3 experience permanent functional deficits. And insufficient plantarflexor power is major #biomechanics cause of reduced walking speed.
Need more attention on rehab to preserve structure to maintain function.
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Need more attention on rehab to preserve structure to maintain function.
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