Exploring the Influence of Flooring Stiffness on Human Gait and Balance in OpenSim: Inquiry and Insights

[Silas Purja]

Dear OpenSim team,

I hope this messsage finds you well. I'm interested in understanding the impact of flooring stiffness on the gait and balance of a human model in OpenSim. Is there a method to import the stiffness properties of the floor into OpenSim, and can you provide insights into how variations in flooring stiffness may affect the simulation results?

Thank you for your assistance.

Sincerely,
Silas

[Carmichael Ong]

There are a couple examples that have models that use foot-floor contact, including Simulation-Based Design to Prevent Ankle Injuries and Sky High: Coordinating Muscles for Optimal Jump Performance.

These examples have models that you can open in the GUI and both look at and adjust the parameters. The two places to see these parameters include under the "Contact Geometry" heading (these will be more related to the shape, location, and geometry of the contact elements), and the "Forces -> Contact Forces -> (force element) -> contact_parameters" (these will be more related to the intrinsic properties of the contact elements).

It's difficult to say how variations in stiffness will affect your specific simulations and results. As a very general comment, softer stiffness usually leads to faster simulations, but this is a tradeoff against making sure that it is validated well for your specific research question. Looking at the literature to see how others have dealt with choosing parameters can be helpful, for example, a paper from Haralabidis et al. 2021, which has a good discussion about choosing contact parameters.

[Silas Purja]

Hi Carmichael,

I wanted to express my sincere thanks for your message and suggestions. I will certainly look into the recommendations you provided.

Many thanks once again.

Best regards,
Silas

[Silas Purja]

Hi Carmimichael,

I hope this message finds you well. Thank you for your response. I was wondering if there is a method to modify the floor stiffness directly, instead of importing the stiffness properties?

Alternatively, if direct modification is not feasible, could you guide me on how to incorporate springs into the floor and adjust the stiffness of these springs?

I appreciate your assistance in clarifying these points.

Many thanks,
Silas