Inverse Dynamics Set Up With AFO

[Catarina Ribeiro]

Hello there,

I wanted to use the Inverse Dynamics tool to determine the ankle moment during walking with an orthosis. Herewith, I've imported an AFO to the model gait2354_simbody and attached its cuff to the tibia through a weldjoint and its foot to the model's foot through a weld constraint.
Now, what I wanted to know is how to define the set up for ID, especially the external loads file. When I apply the external forces to the AFO_foot (as shown below), the values of ankle moment are very small when compared to the moment's values of normal gait.

opensimForum.PNG (79.78 KiB) Viewed 158 times

My question is if the WeldConstraint is enough to design the interaction between the model's foot and the AFO's foot or should I define a Hunt&Crossley force between the calcaneus and the AFO's foot?

Thanks in advance,

Catarina Ribeiro