Attaching and detaching external bodies to the model through XML

[Sanchana Krishnakumar]

I am working on the Lifting full-body (LFB) model. My objective is to add an external box to the model and model a dynamic squat lifting trial. The box should be an external object and attach to the body only during lifting. The aim is to study the effect of interaction forces and the weight of the box during lifting. Is there a way to do this?

Right now I am using the xml editor to add the box as a body to the model and created a weld joint to the hand. But I would like to attach and detach the box during the trial. The version of the xml document is 4000. Are there other models using this version of the xml document that I could use as a reference to define the contact geometries and HuntCrossley forces?. When I use a code snippet from the version 3000 file, I get an error when I try opening the model in the OpenSim. I am quite new to editing models for the OpenSim therefore,any leads would be much appreciated. Thanks in advance.

Regards,
Sanchana