Output files of plug-in-gait_simple model

[CDzialo (Christine Dzialo)]

Hello Lee,

It really depends how you want to interpret the joint reaction forces and moments.

To investigate JRF we usually use RefFrameOutput measures (F,M) which correspond to the KneeJointReactionMoments (F and M) found in the BodyModel.*.Leg.MomentMeasure folder (see AMMR\Body\AAUHuman\LegTLEM\LegMoments.any for more info) and then also read up on the AnyForceMomentMeasure function in the reference manual. RefFrameOutput.F and .M measures are arrays depending on how many reference frames are listed. Since there are two (ThighNode and ShankNode) the 1st set refers to the 1st mentioned ref frame, and the second refers to the 2nd mentioned ref frame (measures should be equal but opposite).

SelectedOutput: terminology

Hi Brent, What happens is that the output Reaction.Fout of a the joint gives the reaction forces that the first node applies on the second node of the joint, in the first node coordinate system. And the AnyForceMomentMeasure gives the forces that are applied to the first node, in the first node coordinate system. That is why you found the two are opposite. Best regards, Sylvain.

Hope this clarifies a bit.

Best Regards,
Christine