When to switch mannequin drivers off?

Main Forum
1

Hi all,

So I am working with Bergamnn et al.s’ shoulder model.
I’ve changed several drivers from simple to fourier and added a GH flexion driver.

However, in the BMSettings, Bergmann et al. switched some mannequin drivers off. (Glenohumeral_Abruction and Glenohumeral_Flexion)

Now I am wondering if I need to adapt these specifications or not?! If I do so, when and how do I need to do this?

I don’t get any errors if I leave the spewcifications as they are defined by Bergamnn et al. just wondring, if it has any inpact on my simulaiton?

Thank you in advance for your help.
Seline

2

Hi Seline,

These mannequin drivers are “soft” constraints, meaning that they could be compromised when kinematics is being solved. And if you add a “hard” constraint on top of the soft one - the system will simply ignore the soft one. The problem might come when you change the kinematic solver type to a one that does not handle overdeterminacy. But otherwise that was our intent to have “replaceable” drivers. Yet it is a little more robust and better practice to have similar number of drivers and free degrees of freedom.

Kind regards,
Pavel

3

Hi Pavel
Thank you for your answer.

In this case I assume everything is fine.