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Knee hyper-extension prediction in Inverse Kinematics analysis

Posted: Sun Aug 11, 2019 2:58 pm

by amiriqbal4u

Hi,

Can OpenSim inverse kinematics predicts knee hyper-extension? I have a c3d data file which was analyzed by C-Motion and shows knee hyper extension of 6-8 degrees. However, in OpenSim inverse kinematic analysis the the knee hyper-extension is not predicted (knee angle range -4 to -70 degrees). Is there a setting which limits the knee angle and suppress hyper-extension? Thank you.

Best regards
Amir

Re: Knee hyper-extension prediction in Inverse Kinematics analysis

Posted: Mon Aug 12, 2019 1:17 pm

by aymanh

Hello,

InverseKinematics enforces the bounds on coordinates as specified in the model file, if you want to modify these bounds you can edit the file or change in the GUI coordinates window, just be aware of the downstream effects (for example are the splines for the knee motion defined for your range, how muscle paths change etc.).

Hope this helps,
-Ayman