How to validate joint stiffness using a prescribed point force.

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Michael McGeehan
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Joined: Wed Feb 07, 2018 2:41 pm

How to validate joint stiffness using a prescribed point force.

Post by Michael McGeehan » Wed Oct 24, 2018 9:13 am

I am currently working to validate a model of a two-segment prosthetic foot. The joint between the forefoot and midfoot of the prosthesis has a known stiffness value which I have modeled as a BushingForce.

I would like to "tune" and ultimately validate the stiffness of the modeled joint to the known stiffness of the same joint on the prosthetic foot. My initial idea is to lock all other joints of the model, simulate application of a vertical point force to the forefoot, and assess the forefoot deflection.

Can anyone comment on methods for simulating the force on the forefoot?

Also, if anybody knows a better and/or simpler method for this validation, I welcome suggestions.

Thank you in advance!
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Ajay Seth
Posts: 136
Joined: Thu Mar 15, 2007 10:39 am

Re: How to validate joint stiffness using a prescribed point force.

Post by Ajay Seth » Wed Oct 24, 2018 12:10 pm

Your approach sounds reasonable and you can apply any force (either a profile you create or the experimental GRF) to any body in the model. Once you've created the model you can apply the force using External Loads tab in the GUI and associate forces (with force vector and point locations as columns) in a .mot file with the forefoot body.
externalLoadsForForwardTool.PNG
externalLoadsForForwardTool.PNG (113.43 KiB) Viewed 268 times
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