Dr. Oliver Demuth

The code and scripts are all archived on Zenodo and GitHub:
doi.org/10.5281/zeno...
github.com/OliverDemuth...

Soft tissue constraints on joint mobility in the avian shoulder Summary: Experimental ex vivo data and in silico simulations shed light on the function of ligaments in the bird (partridge) shoulder joint in maintaining shoulder articulation and constraining joint ...

My recent paper describing the method and application can be found here: doi.org/10.1242/jeb....

I've released version 1.2 of my SDF simulations! This update further improves the runtimes:

- Simple checking for collision between two meshes run at >150 FPS
- Full 6DOF ROM simulations optimising the translations for each rotational pose run at >5.6 FPS
- Ligament path estimation run at >5.1 FPS

I had a great day yesterday at the @ucl-c4ia.bsky.social symposium Anatomy: past, present and future! There were some fantastic talks and I also got to presented my current work on bird flight

The PDF of the News article, Announcing the 2025 Journal of Experimental Biology Outstanding Paper Prize shortlist and winner, by Kathryn Knight. The publishing information at the top states: © 2026. Published by The Company of Biologists | Journal of Experimental Biology (2026) 229, jeb252265. doi:10.1242/jeb.252265. The first sentence of the article says, 'If you're a fan of comparative physiology, clicking on a new issue of Journal of Experimental Biology can feel like being let loose in an opulent store of treats'. The first three shortlisted articles are presented in a box at the top of the second column of text.

Congratulations to all of the remarkable ECRs whose research has been recognised in the 2025 JEB Outstanding Paper Prize shortlist

Find out about each of the shortlisted papers and their outstanding ECR authors

journals.biologists.com/jeb/article/...

I am actively working on some improvements to the code for the ROM simulations. Version 1.1 was released late last year and version 1.2 will come soon. Additionally, I am working on a @blender.org implementation!! 👀

My recent bird shoulder XROMM study got nominated and shortlisted for the @jexpbiol.bsky.social Outstanding Paper Prize! Unfortunately, I did not win but very happy to have been considered!!
If you want to learn more about our study see below thread!

Haolong dongi, amazing new spiny (yes,really) iguanodontian from early cretaceous china #sciart

The code can be found on Zenodo: doi.org/10.5281/zeno... and GitHub: github.com/OliverDemuth...

Soft tissue constraints on joint mobility in the avian shoulder Summary: Experimental ex vivo data and in silico simulations shed light on the function of ligaments in the bird (partridge) shoulder joint in maintaining shoulder articulation and constraining joint ...

We applied these simulations to the shoulder mobility and its soft tissue constraints in Partridges! Read the paper here: doi.org/10.1242/jeb....

The soft tissue simulations calculate the lengths of ligaments from origin to insertion wrapping around the 3D bone meshes, while preventing penetration/impingement. The lengths of these ligaments can then be used to constrain the ROM to a more functional ROM estimate.

The proximity based range of motion simulations, leveraging signed distance fields, allow to simulate physiologically accurate joint behaviour. The translations are optimised for each rotational pose to maximise overlap of the articular surfaces and prevent disarticulation.

Version 1.1 of my SDF simulations are out! This update significantly improves the runtime of all simulations while making the installation a lot easier!

ROM simulations used to take days, now they only take a few hours and include physiological accurate soft tissue constraints!

Top UK scientist says research visa restrictions endanger economy Prof Sir Paul Nurse says the UK is

New President of the @royalsociety.org is going to tackle exorbitant UK visa fees for scientists. We sure need a big change!
www.bbc.co.uk/news/article...

Soft tissue constraints on joint mobility in the avian shoulder Summary: Experimental ex vivo data and in silico simulations shed light on the function of ligaments in the bird (partridge) shoulder joint in maintaining shoulder articulation and constraining joint ...

Joints aren’t just bones 🦴
Ligaments shape how vertebrates move

New study by @oliverdemuth.bsky.social et al in @jexpbiol.bsky.social combines in silico & ex vivo #XROMM of the partridge shoulder to show how ligaments constrain motion 🐦

👉 journals.biologists.com/jeb/article/...

But you are directly competing with them, if you want it or not. You contributed work to Mesozoic Art—you are among a select few artists. Hence you *are* a professional and published artist, no matter your background. You do good work and with such you also have a responsibility

The dependencies (i.e., pytricubic) are currently a bit cumbersome to install for Autodesk Maya but I am working on an update removing pytricubic and only relying on NumPy and SciPy, and in the process improving the runtime by another 5 to 15%(!). Stay tuned!

Soft tissue constraints on joint mobility in the avian shoulder Summary: Experimental ex vivo data and in silico simulations shed light on the function of ligaments in the bird (partridge) shoulder joint in maintaining shoulder articulation and constraining joint ...

The PDF can be found here: doi.org/10.1242/jeb....

While we focused on the bird shoulder, the proposed workflow can be applied to all sorts of joints in the vertebrate skeleton (vertebrae, wrist, hip, knee, toes, jaws, etc). If you want to explore the method please get in touch!

This study would not have been possible without the support of an @eavpalaeo.bsky.social research grant (OED), @erc.europa.eu Horizon 2020 grant (JRH) & @ukri.org FLF (DJF)

The final PDF of our XROMM study on bird shoulders w/ @johnrhutchinson.bsky.social & @fieldpalaeo.bsky.social is now available at @jexpbiol.bsky.social!

🚨 Palaeo jobs alert!! 🚨

Two(!!) postdoc positions available in Cambridge!

1. Human Evolutionary Anatomy: cam.ac.uk/jobs/researc...
2. Evolutionary Biomechanics: cam.ac.uk/jobs/researc...

As part of the @erc.europa.eu funded STEPS project!

🚨 Job position @cam.ac.uk 🚨

Project Coordinator for 5 years at 0.5 FTE on the ERC Funded STEPS project. Closing date for application 2nd January 2026, interviews ~3 weeks later!

Apply here: www.cam.ac.uk/jobs/project...

@cam-archaeology.bsky.social
@erc.europa.eu

A-level English, voluntary work, delayed citizenship: it’s Labour’s Orwellian Two Minutes Hate for immigrants | Nesrine Malik It’s easier for politicians to blame others than to face the truth: Britain has been stripped of the spaces and opportunities that allow for true social integration, says Guardian columnist Nesrine Malik

A-level English, voluntary work, delayed citizenship: it’s Labour’s Orwellian Two Minutes Hate for immigrants | Nesrine Malik

Constrained variation in the internal architecture of avian wing bones Read the free Plain Language Summary for this article on the Journal blog.

Happy to share my first postdoc work published in @funecology.bsky.social ! A huge thank-you to @oliverdemuth.bsky.social @lizzysteell.bsky.social @fieldpalaeo.bsky.social @grumpydrfabre.bsky.social and to @snsf.ch

besjournals.onlinelibrary.wiley.com/doi/10.1111/...

GitHub - OliverDemuth/MayaSignedDistanceFields: Signed distance field-based simulations of joint range of motion and path (ligament) wrapping around obstacles (bones) for Autodesk Maya Signed distance field-based simulations of joint range of motion and path (ligament) wrapping around obstacles (bones) for Autodesk Maya - OliverDemuth/MayaSignedDistanceFields

All code (with instructions) is available on my GitHub: github.com/OliverDemuth... and on Zenodo (with additional data): doi.org/10.5281/zeno.... If you have any questions I am more than happy to help and explain the workflow/pipeline! 11/11

Soft tissue constrained mobility simulations, where rows represent specimens and columns different thresholds for the ligaments.

These simulations can not only be used to measure the lengths in experimental data, but can also constrain osteological ROM measurements to receive more functionally informative ROM estimates. Importantly, they are applicable to all type of joints and even fossils! 10/11

Optimised ligament lengths across the joint mobility and comparison with measurements from dissections. Data points are colour-coded according to the respective ligament and their magnitude

We calculated ligaments across the whole XROMM dataset and compared them to lengths measuared through dissection. It appears that different ligaments have different amounts of elasticity. Potential differences in (primary?) functions? 9/11

Cost function for the ligament optimisation. The minimal length of a ligament from origin to insertion was optained through minimising the deviations from a straight line while the individual ligament points could not intersect with the bone meshes (i.e., their position in the signed distance fields could not be negative). An additional inequality constraint prevented the ligament from rapidly changing directions and restricted the angular offset between two ligament points to approximately 60°.

Similar to the osteological ROM simulation we used a signed distance field representation of the bones to speed up the optimisation process. The minimal length of each ligament was calculated from origin to insertion without any way points intersecting the bones 8/11

Ligaments of the shoulder capsule in the red legged partridge. The ligaments are coloured according to their identity in the different views.

We were not only interested in the osteological range of motion (ROM) but also in the soft tissues constraints surrounding the joint. We simulated the ligaments of the shoulder capsule that prevent excessive movement while enabling contact between the bones during motion 7/11

Cost function for the optimisation of joint articulation. Minimisation of the first term reduces deviation from a previously defined target proximity. The second term improves joint congruency through minimisation of the variance observed in the distance measurements. The minimisation is subjected to the constrain function defined by the signed distance field where measurements could not be negative (i.e., bones intersecting).

Our approach is similar to work by Lee et al. (doi.org/10.1098/rspb...) but implemented in Autodesk Maya with Python. The optimisation approach minimises a cost function that determines joint proximity (cartilage thickness) and congruency (overlap) over a signed distance field 6/11