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Ankle Torque and Contact Forces

Posted: Tue Aug 11, 2020 9:21 am
by njfragni
Hello! I am working to calculate the ankle torque for a gait cycle. I am very new with this program. The issue I am facing is that my values in the swing phase are way too high. I believe it is because I am not considering the contact forces in the model and with the floor. How would I go about applying contact forces to a model. Right now I am using the standard 2392 model and normal.mot file given in the beginners tutorial. Thank you for your time.

Re: Ankle Torque and Contact Forces

Posted: Wed Aug 12, 2020 12:05 am
by mitkof6
Hi Natalie,

As you correctly pointed out, you must include the forces that are applied on the model by the ground (ground reaction forces -> grf). I am not sure if the tutorial that you are referring is intended for inverse dynamics. In the pipeline example:

https://github.com/opensim-org/opensim- ... 54_Simbody

you can use the subject01_walk1_grf.mot file along with the motion file (subject01_walk1_ik.mot) to perform inverse dynamics. For convenience, the tool setup files (.xml) are also provided.