I want to double-check some of the principles as I had some concerns when I switched between different C3D files with different lab Global coordinates:
In the case of using the Mocap model With the generic global coordinates (X, Y, Z),
Are joint reactions always, by default exported in the Local Reference Frame of the join/segment?
For example, in the selected output:
Main>Studies>InverseDynamicsStudy>Output>BodyModel>SelectedOutput>Right>Leg>JointReactionForce
Hip_MediolateralForce
Hip_ProximoDistalForce
Hip_AnteroPosteriorForce
These forces are based on the local coordinates of the joint (Thigh.HipJoint ref), correct?
Following the same SelectedOutput path, when it comes to muscle forces with components (F[0], F[1], F[2]), it is written in the Global coordinates system, correct?
with (F[0], F[1], F[2]) corresponds to X, Y, Z of the Global coordinates system.
If AnyOutputFile is used to export .txt of specific muscles force F,
the exported results of muscles and joints forces will be written by default (F[0], F[1], F[2]) according to the Global reference ( X, Y, Z)?
If AnyMechOutputFileForceExport is used to export all results in .txt with "UseRefFrameOnOff = Off".
all the exported results of muscles and joint forces will be written by default in the Global Reference, correct?
Here the hip reactions will be in terms of F[0], F[1], F[2] and follows the Global coordinates system, correct? rather than following the local referencing of
Hip_MediolateralForce > i.e it doesn't correspond to F[0] or Fx in the Global Ref
Hip_ProximoDistalForce
Hip_AnteroPosteriorForce
However, if "UseRefFrameOnOff = On" and a reference segment is defined,
muscles and joint forces results will be written based on this local reference of the segment, correct?
In case of using a different C3d file with different Global coordinates orientation, all the exported results -based on the global coordinates- will follow the new global coordinates, correct?
i.e its F[0], F[1], F[2] will corresponds to the new X. Y, Z of the new coordinates.
However, hip reactions in terms of
Hip_MediolateralForce
Hip_ProximoDistalForce
Hip_AnteroPosteriorForce
Are independent of the global coordinates, correct?