Questions about the valgus knee braces

Hi

Hello everyone, I just started learning the Anybody. I am glad to use this software to complete my research. I want to use Anybody software to do some evaluation of the valgus knee brace during the gait. But I have some questions, if someone can help me I would really appreciate it :blush:

I exported the CAD file of the brace from Solidworks. It is a valgus brace with straps on the thighs and calves. I want to know what constraints are used to connect the brace and HumanModel.

And I read the article "Modeling and Simulation of a Lower Extremity Powered Exoskeleton". It uses GeneralMuscle to calculate the effect of exoskeleton on people.So I want to ask how do I calculate the effect of the knee brace on the HumanModel?

Best wishes
lss

Hi Iss,

I think there can different ways to address this type of problem depending on how deep the analysis should be.

First of all the standard knee joint is a revolute joint, so it would allow you to read out reaction forces and moments, of the three forces and two moments, but it will not allow you to see the motion change in the as a function of the brace, for this to happen you would need a FDK based knee model.

Concerning the forces between knee and brace i would use the contact elements for this please see this link

It is also possible to use general muscles but they will not allow you to link normal and frictional forces.

Best regards
Søren

Hi Søren

Thank you very much for your help. I read the FDK function and All about FrictionContactMuscles, it helped me a lot. If I use the contact elements between the knee joint and the brace. I want to know how to calculate the force of the brace on the Human during the gait. Is it the Humanmodel drive the brace?How can i understand the interaction between them.:blush:

Best wishes
lss

Hi shanshan,

I would like to recommend you checking some examples in AMMR (such as: AirlinePassenger, Crosstrainer, StandingLift), in which the interaction between human body model and environment model was defined clearly in the corresponding part's codes. Even you can copy the code structure and modify them for your own use. Previously Pavel also guided me like this and I found it's really helpful.

Hope this helps.

Sincerely Yours,
Tracy

Hi Iss,

I agree with the comment from Tracy these model are a good place to look for examples on how to used these elements.

Each contact element will give you the net force as output, this will be a force acting between body and brace.

Best regards
Søren

Hi Tracy

Thank you very much for your help, it helps me a lot. I will check these examples in the AMMR :blush:

Best wishes
lss

Hi Søren

Thank you again for your help :blush:

Best wishes
lss

Hi Søren

Can you recommend me some biomechanics books that are helpful for learning the Anybody software? I don’t know much about biomechanics, so it’s a bit difficult for me to learn the software.Any help I would be really appreciated :blush:

Best regards
lss

Hi Iss,

In terms of learning AnyBody specifically, i would go though the tutorials which you can find in the help menu, this will take you through most of the basic functionality.

For biomechanics in general please have a look at this page https://github.com/demotu/BMC it is new to me, but seem to be a good page to learn many of the basic principles of biomechanics.

Best regards
Søren