Preset muscle forces in StandingLift demo

[Emily (Emily Smith)]

Hi,

I'm conducting some experiments using the StandingLift demo. In order to validate my results I need to know what the preset maximum strength of the muscles are. I know it is possible to define the variable FO when creating muscles from scratch, but am I able to change this parameter easierly as well in the demo example? I can see that the body is created using the GenericBodyModel.

Hope the question makes sense!
Kind regards
Emily

[Bjorn (Bjørn Keller Engelund)]

Hi @Emily

Please correct me if I misunderstood anything.
Each muscle have a Strength parameter where you can find the maximal strength of that muscle
for instance the long head of the biceps brachi can be accesed as Main.HumanModel.BodyModel.Right.ShoulderArm.Mus.biceps_brachii_caput_longum.Strength.
Bear in mind that the values are first computed when starting the analysis, so you will need to run the Initial Positions study as a minimum.

If you want to alter the strength of certain muscles you have several options:

• use the top level handles we have provided to scale the strength of all leg, arm or torso muscles.
  • You can find the handles here Main.HumanModel.StrengthParameters
• use the strength scaling factors of individual segments.
  • Those are found here Main.HumanModel.Scaling.StrengthScaling
• do it for individual muscles.
  • That could be done for the simple shoulder muscle models in this file: ammr\Body\AAUHuman\Arm\muscle-parameters-shoulder-simple.any

Also keep in mind that the strength of each muscle is affected by the anthropometric scaling of the model.

Best regards,
Bjørn
AnyBody Technology

[Emily (Emily Smith)]

Hi again,

Thanks for your quick reply.
So "Strength" is the max muscle strength and "Fm" is the muscle force used.
So thereby I'll be able to calculate the % of the max muscle strength used for each muscle.

When using the GenericBodyModel are the parameters in the simulation then representing an average man (176cm and 75 kg) as in some of your other tutorials?
AND if I wan't to use the Main.HumanModel.StrengthParameters to adjust the strength to represent an average woman, what should the value (90) be changed to?

Thanks for taking your time to help me

Emily