dtpolet @dtpolet@qoto.org

The results are in! Although a majority said (a), for this particular setup, (b) jumps higher.

This is NOT a general rule in biological jumpers, and is particular to how we've set up the problem (notably, no force-velocity relationship) #biomechanics

All that matters is the amount of work done by the muscle. Since there is no force-velocity relationship, the work done is proportional to the shortening distance. Case (b) wins because the larger in-lever allows the muscle to shorten more

We have an intuition that (a) should be better because biological jumpers look like that. But this is to accommodate power-velocity relationships in muscle, which this setup doesn't have.

My intuition was initially drawn to (c), but the physics clearly show (b) as the winner here. A good reminder to check model assumptions!

If anyone has a good real-world example analogous to this setup, let me know! Force-velocity is pervasive, though

Which will jump higher?

Is it better to jump with a long foot or short foot?

The cases below only differ by whether the in-lever or out-lever is bigger. Which will jump higher?

Ignore contraction dynamics & imagine the body is constrained to go straight up.

Answer and discuss below 👇 #biomechanics

Thanks to all who made it to my talk at #SEB2023! For those who couldn't, here's a prerecorded version https://youtu.be/BIwkG6a5WEo

Watch to find out when it's better for a foot to be a foot vs a leg... And how #lizard toes are a bit like wheels 🦎🛞

What does this #3Dprinted device have to do with #Lizard feet? To find out, come to my #SEB2023 talk Fri at 9:30 in Tinto for the Open #Biomechanics session: "Plantigrade feet avoid work through serial linkages"

You might even get a copy to take home (while supplies last)! 🦎👣

For the record, I acknowledge that the wrist contacts the ground, so the forelimbs are unambiguously plantigrade. To my eyes, though, the hindlimbs are digitigrade.

Also, not everyone agrees in the literature; some authors explicitly say mice are digitigrade - e.g.
https://doi.org/10.3389/fbioe.2018.00061

Are #mice and #rats plantigrade or digitigrade?

I've seen a loooot of studies that code them as plantigrade (e.g.
https://doi.org/10.1073/pnas.1814329116)

... but their ankle is well above the ground (e.g. video from https://doi.org/10.3389/fnins.2016.00042)

What am I missing? 🐀 #biomechanics #mammals

"In an effort to be both environmentally and fiscally responsible, [University] will contact only candidates receiving an interview"

Didn't know automated rejection emails were so expensive and polluting 💵 #academicjobs #AcademicLife

My #SICB2023 poster and video presentation on animal #locomotion and passive dynamic #robots are up on SICB+! Head to the meeting website to check them out
https://sicb.econference.io/public/5X9OIbU/main/sessions/9874/31486

Any recommendations for #dinosaur activities for a class of 4-5 year-olds? Visiting my daughter's classroom in a few weeks to talk about #dinosaurs, but coming up short on ideas! I have access to #3dprinting and laser cutter if that helps... #SciComm #education 🦖🦕

Demos nearly ready for my poster presentation at #SICB2023 ! Come to P2-227 tomorrow (Thursday) 430-530 PM to play with these #ComparativeBiomechanics #dynamics #biorobotics