Loads on shoulder and Lower back

[Akshay Desai]

Good afternoon,
I am trying to add loads to my subject on the shoulder (rucksack load). Is it possible to add load to the subject while walking and analyzing different variables like Joint Reaction?
I would also like to add some inclination while walking.

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Thank you.

[Dimitar Stanev]

Hi Akshay,

You can apply a PrescribedForce. Use the xml browser (GUI: Help -> XML Browser) to get the template for this force, which you can add directly into your model (.osim). Otherwise, you can attach a new body, using a weld joint (e.g., no degrees of freedom), that has the mass properties of the sack.

[Akshay Desai]

Hi Akshay,

You can apply a PrescribedForce. Use the xml browser (GUI: Help -> XML Browser) to get the template for this force, which you can add directly into your model (.osim). Otherwise, you can attach a new body, using a weld joint (e.g., no degrees of freedom), that has the mass properties of the sack.

Kindly explain how to attach the new body using a weld joint? I would like to load this weight on the shoulders and lower back of my subject and then plot the forces on the joint.

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Thank you.

[Dimitar Stanev]

Hi,

Please read the user guide to understand how OpenSim modeling framework works:

https://simtk-confluence.stanford.edu/d ... Sim+Models

I do not know the details what you want to do to help you. However, you can use the weld joint and introduce the sack body. The weld joint can be attached to the torso. Also, you can use weld constraints to attach the sack to the opposite side. OpenSim does not permit creating closed kinematic chains through joints, but it is possible to have a joint and a constraint. For example, you can read the publication of Lerner:

https://simtk.org/projects/med-lat-knee/