Muscle Activity in Shoulder Arm

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I'm using a BVH file to transfer motion to my AnyBody model. The default model did not have any muscles on the upper body. So, I adjusted the config settings a bit.

I'm trying to obtain muscle activity in the arms. In the drop-down menu, I only see "Envelope" for both the right and left sides of the shoulder-arm. Is it possible to get the muscle activity for each muscle in the arms?

Here are my config settings:

#define BM_LEG_MODEL LEG_MODEL_TLEM2
#define BM_TRUNK_CERVICAL_MUSCLES ON
#define BM_SCALING SCALING_XYZ
#define BM_MANNEQUIN_DRIVER_DEFAULT ON

#define BM_TRUNK_MUSCLES ON
#define BM_ARM_RIGHT ON
#define BM_ARM_LEFT ON
#define BM_ARM_MUSCLES_RIGHT ON
#define BM_ARM_MUSCLES_LEFT ON

I am a new user, so very specific advice would be a huge help :).

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Also, how do I identify the muscles in the envelope? It gives me the value, but it'd be nice to know which muscle(s) are contributing.

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Hi Essence Raymo,

looks like you are having a similar model like me. If you just want to have the activity of the muscles in the arm you can also just set the following settings to "off":
#define BM_TRUNK_CERVICAL_MUSCLES
#define BM_MANNEQUIN_DRIVER_DEFAULT
#define BM_TRUNK_MUSCLES

Also you can set the muscles of the legs to "off":
#define BM_LEG_MUSCLES_RIGHT OFF
#define BM_LEG_MUSCLES_LEFT OFF
so you can save some time in calculation.

As I need also the activity of the deltoid, I am using the new deltoid wrapping:

#define BM_ARM_DELTOID_WRAPPING DELTOID_WRAPPING_ELIPSOIDS

Also if you want to specify that the 3HILL model is used, you can specify the following:
#define BM_ARM_MUSCLES_LEFT_MUSCLES_3E_HILL_
or of course for the right arm or both.

I get the activity in form of text data.
For this got to Chart 1, Studies, inverseDynamicsStudy, Output, Bodymodel, Right (or left), ShoulderArm, Mus.
And then you can see every muscle of the shoulder and arm and click on the activity to see a figure of it.
If you want to save the results you can click on the "report as" symbol and choose the data type you want to get.

Hope i could help you,

And just because of interest: Do you use motion capture data? From which company and which muscles do you want to look at?

Kind regards,

Michael

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Hi Essence, Michael,

Thanks for the answer Michael :slight_smile:

I will just mention a few things additionally.

The deltoid muscles use the Elipsoid wrapping by default, so it's also the same if it is not set in the BM config file.

There is also the option of using AnyOutputFile to export the outputs of interest as the simulation runs instead of manually saving the outputs from the chart.

The Envelope only shows the maximum. Unfortunately, you will have to find the exact muscle yourself. If it helps, you can use the * character to plot the activity of all the muscles in the chart view:
BodyModel.Right.ShoulderArm.Mus.*.Activity

Best regards,
Dave

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Hi Michael,

Thank you for your response. I changed my config settings to your reccomendations; however, I am still not seeing the muscle activity in in SelectedOutput Folder.
I am using Xsens motion capture (in the form of a bvh file). I wish to look at all the muscles available in the Anybody Software. I wish to identify key muscles / muscle groups in my model.

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Hi Divyaksh,

Thank you for the additional information! I am struggling to find the path for muscle activity. So, would I still be able to use AnyOutputFile to output the muscle activity data?

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Hi Essence,

In your chart, you can paste the following, for example for biceps: Main.Studies.InverseDynamicStudy.Output._Main.HumanModel.BodyModel.Right.ShoulderArm.Mus.biceps_brachii_caput_breve.Activity

Likewise, you can expand the tree in the chart view. Each . represents a level.

You should still be able to use AnyOutputFile. Please see the reference manual; there are also demo examples to show how the classes work.

Best regards,
Dave

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