Flocal in AnyForce3D



I added AnyForce3D to the shank of the GaitVaughan model.I saw in the tutorial that the Flocal property makes the force perpendicular to the node.But after I used Flocal, I found that the force is not always vertical in motion.Can you tell me how to make the force always perpendicular to the node? Thank you very much.

Best Regards