Definition of total forces.

Main Forum
1

Hello, I’m new to AnyBody.
In the AMMR, there are many application that include below script in the study section of AnyScript file:

//Size of total force in the L5 Sacrum joint
AnyVar L5SacrumReac = (Main.Model.HumanModel.Trunk.JointsLumbar.L5SacrumJnt.Constraints.Reaction.Fout[0]^2+ Main.Model.HumanModel.Trunk.JointsLumbar.L5SacrumJnt.Constraints.Reaction.Fout[1]^2+ Main.Model.HumanModel.Trunk.JointsLumbar.L5SacrumJnt.Constraints.Reaction.Fout[2]^2)^0.5;

Is this only define the intradiscal COMPRESSIVE force?

When I try to applied external force acting in axial axis, the total force show an increase pattern (become big) instead of decreasing. I expected a decrease value since we tract/stretch the spine.

Can anyone help me?

2

Hi,

If you find a folder called SelectedOutput in the model tree - you could find all lumbar spine reaction forces defined in anatomic coordinates.

But if you need to be reported in a certain way you can create an object of AnyForceMomentMeasure2 class that would report exactly in the ref. frame you need. This is very recommended! Please check ref. manual for the details.

Regarding the unexpected result - it is really hard to say what you did wrong without seeing the actual code. Please provide more details.

Kind regards,
Pavel