MomentArms of External Forces in Matlab

[Romain LEBERRE]

Hi,

I am performing a static analysis of a 6DOF tibiofemoral joint with ligaments and articular contact model subject to external forces using the ForwardTool. I run the simulation and postprocess the results through API in Matlab.

Actually, I'd like to estimate the individual contribution of all forces actuating on the articulation (ligaments, articular contact, gravity and external load) at equilibrium in terms of generalized forces. To that end I need the moment arm vector of each applied force. I could get the ligaments moment arms through the computeMomentArm method. Nevertheless, I could't find a similar method for ExternalForce instances and the MomentArmSolver seems to be unavailable yet in Matlab.

So I wonder what would be the easiest way to solve this issue. Perhaps the IAA analysis could manage it but actually this analysis makes the forward simulation crash, probably because of the lack of muscles in my model.

Thanks for your help.

Romain