Verification of Inverse Dynamics moments of neck joints without external loads applied

[Pavlos Silvestros]

Hello all,

I am attempting to run an IK and ID pipeline in-order to estimate the individual internal joint moments of the neck joints prior to impact in a tackling scenario. Currently I am running this pipeline with only the pelvis and upper body thus neglecting ground contact forces at the feet. As I am only interested in the pre-contact phase the ID is ran with no external loads prescribed only the kinematics from the IK.

I am wanting to verify that the generalised moments I get from the ID when using this model (pelvis and upper body) and ID setup (no external loads) are not incorrect. As an initial step I check the same trials using a complete body model and external loads applied to the feet and the ID moments at the neck joints were similar to my original model and ID setup.

In short, I am using a pelvis and upper body model to estimate the ID moments at the neck during tasks with no external forces applied to the model other than the ground reaction forces at the feet which are being neglected. My assumption for this is that they will not have a large effect as the ID is solved from distal to proximal segments of the model's topology tree.

If anyone has any comments or considerations I would be very grateful if they share them with me.

Thank you in advance,
Pavlos