Hi @Andrea
Great to hear you are making progress!
The compression and shear force of the L5-S1 joint can be found as part of the InverseDynamicStudy's selected output.
The path will look somethinf like this, depending on your model structure.
...InverseDynamicStudy.Output.BodyModel.SelectedOutput.Trunk.JointReactionForce.L5SacrumMedioLateralForce In the same folder you can find the remaining two directions of the joint reaction force.
Best regards,
Bjørn
AnyBody Technology