Marker placement

Hi,
Is it possible to run the ‘GaitLowerExtremity’ of the repository without markers on the upper body?
Regards
Chan

Hi Chan,

Yes this is possible,

Instead of the markers used now you will need to drive the motion of the spine with something else.

The simplest solution is to drive the PelvisThrorax rotation to zero and drive the neck joint, this will make the upper body entirely stiff. This is an easy solution but it will look a bit unrealistic.

The other option is to enforce the upperbody to stay just above the pelvis sideways and then lock the flex/ext and rotation, please see the example below form the GaitUniMiami model in the repository:

// Aliases for convenient referencing
  AnyFolder &JntPos=..Mannequin.Posture;  
  AnyFolder &JntVel=..Mannequin.PostureVel;
  
 AnyKinEqSimpleDriver PelvisThoraxDriver ={
    AnyKinMeasureOrg &ref1= ...HumanModel.Interface.Trunk.PelvisThoraxExtension;
    AnyKinMeasureOrg &ref3=     ...HumanModel.Interface.Trunk.PelvisThoraxRotation;
    DriverPos={0,0}; 
    DriverVel={0,0};
  };
  
  //This is an etsimation of the upper body motion it will enforce that the head is kept above the pelvis medial/laterally
  AnyKinEqSimpleDriver LateralBendDriver ={
    AnyKinLinear lin ={
      AnySeg &ref1=  ....HumanModel.Trunk.SegmentsLumbar.PelvisSeg;
      AnySeg &ref2=  ....HumanModel.Trunk.SegmentsThorax.SkullSeg;
    };
    DriverPos={0};
    DriverVel={0};
    MeasureOrganizer={1};
  };
  
  AnyKinEqSimpleDriver NeckDrv={
    AnyKinMeasureOrg &ref1= ...HumanModel.Interface.Trunk.NeckJoint; 
    DriverPos={0};
    DriverVel={0};
    Reaction.Type={Off};
  };

Best regards
Søren