Weird thoracic/abdo posture during movement from AMMR4-Beta

Dear Hamed,

I think I have figured out why the model spine is not following mocap driver. I have disabled the extra drivers for the thorax below and the output looks much better than the previous simulation

BM_MANNEQUIN_DRIVER_SKULL_THORAX_FLEXION
BM_MANNEQUIN_DRIVER_SKULL_THORAX_LATERALBENDING
BM_MANNEQUIN_DRIVER_SKULL_THORAX_ROTATION

BM_MANNEQUIN_DRIVER_PELVIS_THORAX_LATERAL_BENDING
BM_MANNEQUIN_DRIVER_PELVIS_THORAX_ROTATION
BM_MANNEQUIN_DRIVER_PELVIS_THORAX_EXTENSION

So, my follow up questions are:-

  1. I have been reading this forum post and I just wondering if there is any value for me to add weak drivers into my simulation given that I have slightly more (extensive) markers on the thorax and spine compared to the issue described in that post?
  2. Given that I am simulating a lot of movement related to the spine for my current study simulation, such as this bending forward, and I am using several markers on the spine, should I run ParameterIdentification study on C3D mocap data that involve movement in the spine (e.g. bending forward and twisting)? Or it does not really matter because it is simply just optimising the segment length and not joint centre? [My primary focus on this simulation is kinematics and loading on the vertebrae and I am using one marker for each vertebra tracked and not a cluster marker; I am using #SPINE_MARKERS_SINGLE]

Look forward to your response. Thank you.

Kind regards,
Faizal