Muscle overload during inverse kinetic analysis

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@zzs22500 Just a quick thought to your original question about overloaded muscles in the model.

I think it could also be caused by the Psoas muscles trying to provide the necessary force to the trunk and upper body. That is really not what we want here since we don't have any markers on the upper-body. So the dynamics could be completely wrong.

What you should do is add reaction-forces to all the joints of the upper body. Only then can we disregard the upper body completely.

Try to add the following to your model:

  Main.HumanModel.BodyModel.Trunk ={
    AnyReacForce SpineJointReactions={
      AnyKinMeasure &jnt1=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.T1C7Jnt;
      AnyKinMeasure &jnt2=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.C7C6Jnt;
      AnyKinMeasure &jnt3=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.C6C5Jnt;
      AnyKinMeasure &jnt4=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.C5C4Jnt;
      AnyKinMeasure &jnt5=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.C4C3Jnt;
      AnyKinMeasure &jnt6=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.C3C2Jnt;
      AnyKinMeasure &jnt7=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.C2C1Jnt;
      AnyKinMeasure &jnt8=Main.HumanModel.BodyModel.Trunk.JointsCervicalSpine.C1C0Jnt;
      AnyKinMeasure &jnt9=Main.HumanModel.BodyModel.Trunk.JointsLumbar.L5SacrumJnt;
      AnyKinMeasure &jnt10=Main.HumanModel.BodyModel.Trunk.JointsLumbar.L4L5Jnt;
      AnyKinMeasure &jnt11=Main.HumanModel.BodyModel.Trunk.JointsLumbar.L3L4Jnt;
      AnyKinMeasure &jnt12=Main.HumanModel.BodyModel.Trunk.JointsLumbar.L2L3Jnt;
      AnyKinMeasure &jnt13=Main.HumanModel.BodyModel.Trunk.JointsLumbar.L1L2Jnt;
      AnyKinMeasure &jnt14=Main.HumanModel.BodyModel.Trunk.JointsLumbar.T12L1Jnt;
    };
  };

I think that will solve your problem :slight_smile:

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