Adding a Spring Between Vertebrae to Simulate Spinal Stabilization

[Filip Ryšavý]

Dear OpenSim Community,

My name is Filip, and I am a student currently working on a project where I aim to simulate spinal stabilization by adding a spring element between vertebrae in an OpenSim model. Specifically, I am focusing on the L5-S1 segment and trying to model the stabilization effect on adjacent segment loads during dynamic simulations.

I ve successfully managed to implement a PathSpring between the segments using MATLAB, but I am struggling with setting the correct parameters and ensuring that the spring is anatomically and functionally accurate. My questions are as follows:

Positioning the spring: What is the best approach to determine the exact start and end points for the spring? Should I use specific offsets or reference frames tied to the joints?

Spring parameters: How do I decide on appropriate values for stiffness, damping, and resting length to simulate a realistic stabilization effect?

Validation: Are there any best practices for validating the placement and behavior of the spring in OpenSim? For example, should I expect a specific change in load distribution on stabilized versus non-stabilized segments?

I would be incredibly grateful for any advice, example scripts, or references to similar projects. Thank you in advance for your guidance and support!

Kind regards,
Filip