# Calculating joint reaction force & torque

Hi,

Can I derive joint reaction force and torque if I have ground reaction
force data?
Muscle forces are shown in the ChartFX after inverse dynamic analysis.

Sincerely,
Sungwoo Park

Hi Sungwoo

Yes this is possible.

If you have a model with measured forces applied at boot feet, you can run
the model with no muscles and read out the moments from the moment
generating muscles in each joint. In the bodymodel you will find a folder
named JointMuscles, and for each dof there is a pos and neg muscle
generating the moment.

If you then run the model with the real muscles you can read out the
reaction forces from the joints directly by looking at the joint reaction
forces. This you do by finding the property Constraint.Reaction.Fout in each
of the joints. Please note that the reaction forces will only be realistic
in the model with the real muscles because the muscles contractions also
create reactions, this contribution is not included in the version with the
moment generating muscle.

This two step procedure is the simplest way to do this, but it is only
possible if you have measured loads applied, otherwise you have to sum of
the moment contribution from each muscle around each dof, using the the
AnyForceMomentMeasure object.

Hope this helps

Happy new year

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of cizofu11
Sent: 26 December 2008 09:34
To: anyscript@yahoogroups.com
Subject: [AnyScript] Calculating joint reaction force & torque

Hi,

Can I derive joint reaction force and torque if I have ground reaction
force data?
Muscle forces are shown in the ChartFX after inverse dynamic analysis.

Sincerely,
Sungwoo Park

[Non-text portions of this message have been removed]

Thank you for the tips. I could see the joint forces as following your
direction.
Â
ThenÂ what if I want to calculate joint torque without repository model, but the
simple model that I made by myself? I can’t include no muscle model and
JointMuscles file. Then should I use AnyForceMomentMeasure object? Could you
show me how to use it? I’m wondering how I can make a code dirctly into my own
AnyScript to calculate joint torque. Thank you!

— On Sat, 1/3/09, AnyScript Support <anyscriptsup@anybodytech.com> wrote:

From: AnyScript Support <anyscriptsup@anybodytech.com>
Subject: RE: [AnyScript] Calculating joint reaction force & torque
To: anyscript@yahoogroups.com
Date: Saturday, January 3, 2009, 7:56 AM

Hi Sungwoo

Yes this is possible.

If you have a model with measured forces applied at boot feet, you can run
the model with no muscles and read out the moments from the moment
generating muscles in each joint. In the bodymodel you will find a folder
named JointMuscles, and for each dof there is a pos and neg muscle
generating the moment.

If you then run the model with the real muscles you can read out the
reaction forces from the joints directly by looking at the joint reaction
forces. This you do by finding the property Constraint.Reaction .Fout in each
of the joints. Please note that the reaction forces will only be realistic
in the model with the real muscles because the muscles contractions also
create reactions, this contribution is not included in the version with the
moment generating muscle.

This two step procedure is the simplest way to do this, but it is only
possible if you have measured loads applied, otherwise you have to sum of
the moment contribution from each muscle around each dof, using the the
AnyForceMomentMeasu re object.

Hope this helps

Happy new year

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogrou ps.com [mailto:anyscript@yahoogrou ps.com] On Behalf
Of cizofu11
Sent: 26 December 2008 09:34
To: anyscript@yahoogrou ps.com
Subject: [AnyScript] Calculating joint reaction force & torque

Hi,

Can I derive joint reaction force and torque if I have ground reaction
force data?
Muscle forces are shown in the ChartFX after inverse dynamic analysis.

Sincerely,
Sungwoo Park

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Hi Sungwoo

In the file section of group there is a “smallexamples” folder, in this
folder there is a example named AnyForceMomentMeasure.any , it gives small
example on how to use this facility.

If you have any further questions after having seen this example, please ask
again.

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of Sungwoo Park
Sent: 20 January 2009 03:00
To: anyscript@yahoogroups.com
Subject: RE: [AnyScript] Calculating joint reaction force & torque

Thank you for the tips. I could see the joint forces as following your
direction.

Then what if I want to calculate joint torque without repository model, but
the simple model that I made by myself? I can’t include no muscle model and
JointMuscles file. Then should I use AnyForceMomentMeasure object? Could you
show me how to use it? I’m wondering how I can make a code dirctly into my
own AnyScript to calculate joint torque. Thank you!

— On Sat, 1/3/09, AnyScript Support <anyscriptsup@
<mailto:anyscriptsup%40anybodytech.com> anybodytech.com> wrote:

From: AnyScript Support <anyscriptsup@
<mailto:anyscriptsup%40anybodytech.com> anybodytech.com>
Subject: RE: [AnyScript] Calculating joint reaction force & torque
To: anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com
Date: Saturday, January 3, 2009, 7:56 AM

Hi Sungwoo

Yes this is possible.

If you have a model with measured forces applied at boot feet, you can run
the model with no muscles and read out the moments from the moment
generating muscles in each joint. In the bodymodel you will find a folder
named JointMuscles, and for each dof there is a pos and neg muscle
generating the moment.

If you then run the model with the real muscles you can read out the
reaction forces from the joints directly by looking at the joint reaction
forces. This you do by finding the property Constraint.Reaction .Fout in
each
of the joints. Please note that the reaction forces will only be realistic
in the model with the real muscles because the muscles contractions also
create reactions, this contribution is not included in the version with the
moment generating muscle.

This two step procedure is the simplest way to do this, but it is only
possible if you have measured loads applied, otherwise you have to sum of
the moment contribution from each muscle around each dof, using the the
AnyForceMomentMeasu re object.

Hope this helps

Happy new year

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogrou ps.com [mailto:anyscript@yahoogrou ps.com] On
Behalf
Of cizofu11
Sent: 26 December 2008 09:34
To: anyscript@yahoogrou ps.com
Subject: [AnyScript] Calculating joint reaction force & torque

Hi,

Can I derive joint reaction force and torque if I have ground reaction
force data?
Muscle forces are shown in the ChartFX after inverse dynamic analysis.

Sincerely,
Sungwoo Park

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Hi, Soren
Â
I checked the file you mentioned. And I got some questions.
If IÂ want to calculate joint torque of ankle, then should I put the ankle joint
reaction force(location of the force)Â for AnyForceBase and the joint node for
AnyRefNode? am I right?
If it’s true, then is it alright to put either shank segment’s ankle joint node
or foot segment’s ankle joint node for AnyRefNode? And does this
AnyForceMomentMeasure class include all the muscles in its calculation
automatically? or should I put any kind of muscle information into this class?
Thank you.
Â
Sincerely,
Sungwoo Park

— On Wed, 1/21/09, AnyScript Support <anyscriptsup@anybodytech.com> wrote:

From: AnyScript Support <anyscriptsup@anybodytech.com>
Subject: RE: [AnyScript] Calculating joint reaction force & torque
To: anyscript@yahoogroups.com
Date: Wednesday, January 21, 2009, 8:41 AM

Hi Sungwoo

In the file section of group there is a “smallexamples” folder, in this
folder there is a example named AnyForceMomentMeasu re.any , it gives small
example on how to use this facility.

If you have any further questions after having seen this example, please ask
again.

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogrou ps.com [mailto:anyscript@yahoogrou ps.com] On Behalf
Of Sungwoo Park
Sent: 20 January 2009 03:00
To: anyscript@yahoogrou ps.com
Subject: RE: [AnyScript] Calculating joint reaction force & torque

Thank you for the tips. I could see the joint forces as following your
direction.

Then what if I want to calculate joint torque without repository model, but
the simple model that I made by myself? I can’t include no muscle model and
JointMuscles file. Then should I use AnyForceMomentMeasu re object? Could you
show me how to use it? I’m wondering how I can make a code dirctly into my
own AnyScript to calculate joint torque. Thank you!

— On Sat, 1/3/09, AnyScript Support <anyscriptsup@
<mailto:anyscriptsu p%40anybodytech. com> anybodytech. com> wrote:

From: AnyScript Support <anyscriptsup@
<mailto:anyscriptsu p%40anybodytech. com> anybodytech. com>
Subject: RE: [AnyScript] Calculating joint reaction force & torque
To: anyscript@yahoogrou <mailto:anyscript% 40yahoogroups. com> ps.com
Date: Saturday, January 3, 2009, 7:56 AM

Hi Sungwoo

Yes this is possible.

If you have a model with measured forces applied at boot feet, you can run
the model with no muscles and read out the moments from the moment
generating muscles in each joint. In the bodymodel you will find a folder
named JointMuscles, and for each dof there is a pos and neg muscle
generating the moment.

If you then run the model with the real muscles you can read out the
reaction forces from the joints directly by looking at the joint reaction
forces. This you do by finding the property Constraint.Reaction .Fout in
each
of the joints. Please note that the reaction forces will only be realistic
in the model with the real muscles because the muscles contractions also
create reactions, this contribution is not included in the version with the
moment generating muscle.

This two step procedure is the simplest way to do this, but it is only
possible if you have measured loads applied, otherwise you have to sum of
the moment contribution from each muscle around each dof, using the the
AnyForceMomentMeasu re object.

Hope this helps

Happy new year

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogrou ps.com [mailto:anyscript@ yahoogrou ps.com] On
Behalf
Of cizofu11
Sent: 26 December 2008 09:34
To: anyscript@yahoogrou ps.com
Subject: [AnyScript] Calculating joint reaction force & torque

Hi,

Can I derive joint reaction force and torque if I have ground reaction
force data?
Muscle forces are shown in the ChartFX after inverse dynamic analysis.

Sincerely,
Sungwoo Park

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Hi Sungwoo,

There is also a detailed explanation of the AnyForceMomentMeasure object in
the reference manual that you should look at. I also recommend you to read
the paragraph about AnyForceMomentMeasure2 which is a more general tool than
AnyForceMomentMeasure.

The member AnyForceBase is the list of the forces to include in the measure.
By default no forces are included. So if you want the moment generated by
the muscles in the ankle joint you have to include all the needed muscles as
AnyForceBase.
You can freely use the joint node from the foot or the shank depending on
which segment you want to be the reference (on which one is the torque
applied). Notice that the resulting moment is always given in global
coordinate system.

Best regards,
Sylvain, AnyBody Support

-----Original Message-----
From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of Sungwoo Park
Sent: 22. januar 2009 06:28
To: anyscript@yahoogroups.com
Subject: RE: [AnyScript] Calculating joint reaction force & torque

Hi, Soren
Â
I checked the file you mentioned. And I got some questions.
If IÂ want to calculate joint torque of ankle, then should I put the ankle
joint reaction force(location of the force)Â for AnyForceBase and the joint
node for AnyRefNode? am I right?
If it’s true, then is it alright to put either shank segment’s ankle joint
node or foot segment’s ankle joint node for AnyRefNode? And does this
AnyForceMomentMeasure class include all the muscles in its calculation
automatically? or should I put any kind of muscle information into this
class?
Thank you.
Â
Sincerely,
Sungwoo Park

— On Wed, 1/21/09, AnyScript Support <anyscriptsup@anybodytech.com> wrote:

From: AnyScript Support <anyscriptsup@anybodytech.com>
Subject: RE: [AnyScript] Calculating joint reaction force & torque
To: anyscript@yahoogroups.com
Date: Wednesday, January 21, 2009, 8:41 AM

Hi Sungwoo

In the file section of group there is a “smallexamples” folder, in this
folder there is a example named AnyForceMomentMeasu re.any , it gives small
example on how to use this facility.

If you have any further questions after having seen this example, please ask
again.

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogrou ps.com [mailto:anyscript@yahoogrou ps.com] On
Behalf
Of Sungwoo Park
Sent: 20 January 2009 03:00
To: anyscript@yahoogrou ps.com
Subject: RE: [AnyScript] Calculating joint reaction force & torque

Thank you for the tips. I could see the joint forces as following your
direction.

Then what if I want to calculate joint torque without repository model, but
the simple model that I made by myself? I can’t include no muscle model and
JointMuscles file. Then should I use AnyForceMomentMeasu re object? Could
you
show me how to use it? I’m wondering how I can make a code dirctly into my
own AnyScript to calculate joint torque. Thank you!

— On Sat, 1/3/09, AnyScript Support <anyscriptsup@
<mailto:anyscriptsu p%40anybodytech. com> anybodytech. com> wrote:

From: AnyScript Support <anyscriptsup@
<mailto:anyscriptsu p%40anybodytech. com> anybodytech. com>
Subject: RE: [AnyScript] Calculating joint reaction force & torque
To: anyscript@yahoogrou <mailto:anyscript% 40yahoogroups. com> ps.com
Date: Saturday, January 3, 2009, 7:56 AM

Hi Sungwoo

Yes this is possible.

If you have a model with measured forces applied at boot feet, you can run
the model with no muscles and read out the moments from the moment
generating muscles in each joint. In the bodymodel you will find a folder
named JointMuscles, and for each dof there is a pos and neg muscle
generating the moment.

If you then run the model with the real muscles you can read out the
reaction forces from the joints directly by looking at the joint reaction
forces. This you do by finding the property Constraint.Reaction .Fout in
each
of the joints. Please note that the reaction forces will only be realistic
in the model with the real muscles because the muscles contractions also
create reactions, this contribution is not included in the version with the
moment generating muscle.

This two step procedure is the simplest way to do this, but it is only
possible if you have measured loads applied, otherwise you have to sum of
the moment contribution from each muscle around each dof, using the the
AnyForceMomentMeasu re object.

Hope this helps

Happy new year

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogrou ps.com [mailto:anyscript@ yahoogrou ps.com] On
Behalf
Of cizofu11
Sent: 26 December 2008 09:34
To: anyscript@yahoogrou ps.com
Subject: [AnyScript] Calculating joint reaction force & torque

Hi,

Can I derive joint reaction force and torque if I have ground reaction
force data?
Muscle forces are shown in the ChartFX after inverse dynamic analysis.

Sincerely,
Sungwoo Park

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

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