The joint moments in MoCapModel

Hi, everyone.

I loaded the MoCapModel and finished the inverse dynamics analysis.

In the char 2D/3D, the calculation results of ‘SacrumPelvisFlexion ExtensionMoment’, ‘SacrumPelvisAxialMoment’ and ‘SacrumPelvisLateralMoment’ are as attached.
We can see that the values are not zero. But In the any file ‘AnyBody.6.0\AMMR\Body\AAUHuman\Trunk\JointsLumbar.any’, the joint between Sacram and Pelvis is AnySphericalJoint, so I think the moments should be zero.

Could you tell me why there are three moments and the values are nonzero?

Thanks very much !


Hi Jing,

It is true this is a spherical joint but it has been equipped with an reaction force because it is considered rigid.

The reactions you see is from this reaction force.

Best regards