Forums Anyscript.org  

Go Back   Forums Anyscript.org > Archive > AnyScript Message Archive

Notices

 
 
Thread Tools Display Modes
  #1  
Old 03-16-2009, 02:21 PM
dc_pete
Guest
 
Posts: n/a
Default GaitUniMiami

Hi,
I'm trying to build a model of an 8 yr old during a gait cycle. As the gait
between this age and adult gait is not too different, I'm adapting the
GaitUniMiami model using scaling methods to adjust the model anthropometrics.
I've have changed the scaling of the skeletal segments based upon a define body
weight and height, through altering the AnyMan.any file so the
AnthroSegmentLengths file is parameterised (so it is similar to that of the
scaling tutorial). Although the model rescales, the feet of the skeleton not
longer contact the force plate. The inverse dynamics still work and compute
muscle forces. Therefore, I wondered if the model should contact the ground, or
if this is just graphical and the muscle forces can be presumed accurate.
Many thanks
Pete

  #2  
Old 03-17-2009, 03:23 PM
AnyScript Support
Guest
 
Posts: n/a
Default RE: [AnyScript] GaitUniMiami

Hello Pete,

If you just scale the model it will not deliver the right results. What is
your approach for the ground reaction forces?

Best regards,

Sebastian



_____

From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of dc_pete
Sent: 16. marts 2009 14:22
To: anyscript@yahoogroups.com
Subject: [AnyScript] GaitUniMiami



Hi,
I'm trying to build a model of an 8 yr old during a gait cycle. As the gait
between this age and adult gait is not too different, I'm adapting the
GaitUniMiami model using scaling methods to adjust the model
anthropometrics.
I've have changed the scaling of the skeletal segments based upon a define
body weight and height, through altering the AnyMan.any file so the
AnthroSegmentLengths file is parameterised (so it is similar to that of the
scaling tutorial). Although the model rescales, the feet of the skeleton not
longer contact the force plate. The inverse dynamics still work and compute
muscle forces. Therefore, I wondered if the model should contact the ground,
or if this is just graphical and the muscle forces can be presumed accurate.

Many thanks
Pete





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

  #3  
Old 03-18-2009, 09:00 AM
simon njiengoue
Guest
 
Posts: n/a
Default RE: [AnyScript] GaitUniMiami

Hi Pete !!
It good your idea to scale the model, but you must scale with the same ratio the
mannequin,the folder which contain all sensors. You try to look if you can
change the value in folder Environment and JointAndDrivers.
Once*you do that, you can simulate and compare the result.
*
Best regards
Simon

--- En date de*: Mar 17.3.09, AnyScript Support <anyscriptsup@anybodytech..com>
a écrit*:


De: AnyScript Support <anyscriptsup@anybodytech.com>
Objet: RE: [AnyScript] GaitUniMiami
À: anyscript@yahoogroups.com
Date: Mardi 17 Mars 2009, 15h23






Hello Pete,

If you just scale the model it will not deliver the right results. What is
your approach for the ground reaction forces?

Best regards,

Sebastian

_____

From: anyscript@yahoogrou ps.com [mailto:anyscript@yahoogrou ps.com] On Behalf
Of dc_pete
Sent: 16. marts 2009 14:22
To: anyscript@yahoogrou ps.com
Subject: [AnyScript] GaitUniMiami

Hi,
I'm trying to build a model of an 8 yr old during a gait cycle. As the gait
between this age and adult gait is not too different, I'm adapting the
GaitUniMiami model using scaling methods to adjust the model
anthropometrics.
I've have changed the scaling of the skeletal segments based upon a define
body weight and height, through altering the AnyMan.any file so the
AnthroSegmentLength s file is parameterised (so it is similar to that of the
scaling tutorial). Although the model rescales, the feet of the skeleton not
longer contact the force plate. The inverse dynamics still work and compute
muscle forces. Therefore, I wondered if the model should contact the ground,
or if this is just graphical and the muscle forces can be presumed accurate..

Many thanks
Pete

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



















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

  #4  
Old 03-18-2009, 06:27 PM
Pete Watson
Guest
 
Posts: n/a
Default RE: [AnyScript] GaitUniMiami

Hi Sebastian
Thanks for your reply (and simon). I don’t quite understand how to scale the
model correctly so apologies for all the questions.
Unfortunately, at the moment I don’t have any ground reaction forces for the
age I’m modelling at the moment. So - is it possible to alter the model so the
existing ground reaction forces are reduced to a reasonable percentage of the
applied scaled body weight during the gait cycle. Or do I need reaction forces
for the age I am trying to model for the inverse to work?
For later reference when we plan to obtain juvenile gait data – do the c3d
files have to obtained in a specific marker set up (I’m trying to use a 6
D.O.F. set up but it does integrate with the model)
Many thanks
Pete
--- On Tue, 17/3/09, AnyScript Support <anyscriptsup@anybodytech.com> wrote:


From: AnyScript Support <anyscriptsup@anybodytech.com>
Subject: RE: [AnyScript] GaitUniMiami
To: anyscript@yahoogroups.com
Date: Tuesday, 17 March, 2009, 2:23 PM






Hello Pete,

If you just scale the model it will not deliver the right results. What is
your approach for the ground reaction forces?

Best regards,

Sebastian

_____

From: anyscript@yahoogrou ps.com [mailto:anyscript@yahoogrou ps.com] On Behalf
Of dc_pete
Sent: 16. marts 2009 14:22
To: anyscript@yahoogrou ps.com
Subject: [AnyScript] GaitUniMiami

Hi,
I'm trying to build a model of an 8 yr old during a gait cycle. As the gait
between this age and adult gait is not too different, I'm adapting the
GaitUniMiami model using scaling methods to adjust the model
anthropometrics.
I've have changed the scaling of the skeletal segments based upon a define
body weight and height, through altering the AnyMan.any file so the
AnthroSegmentLength s file is parameterised (so it is similar to that of the
scaling tutorial). Although the model rescales, the feet of the skeleton not
longer contact the force plate. The inverse dynamics still work and compute
muscle forces. Therefore, I wondered if the model should contact the ground,
or if this is just graphical and the muscle forces can be presumed accurate.

Many thanks
Pete

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



















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

  #5  
Old 03-19-2009, 11:22 AM
AnyScript Support
Guest
 
Posts: n/a
Default RE: [AnyScript] GaitUniMiami

Hi Pete,

In my opinion it's not the best solution to simply scale the ground reaction
forces. It will be difficult to get good results out of this. You could
model the ground contact with reaction forces, which jump in with
conditional contact when the foot hits the ground. Please have a look at the
tutorial about this. But in this case you have to model also the upper body
in a proper way to get the right forces. So, obviously the best solution is
to get a consistent dataset for motion and force data from an experiment.
You can basically use any Marker set you like. Basically, the more markers,
the better. Especially on the foot there should be enough markers, at least
3.

Best regards,

Sebastian



_____

From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of Pete Watson
Sent: 18. marts 2009 18:28
To: anyscript@yahoogroups.com
Subject: RE: [AnyScript] GaitUniMiami





Hi Sebastian
Thanks for your reply (and simon). I don't quite understand how to scale the
model correctly so apologies for all the questions.
Unfortunately, at the moment I don't have any ground reaction forces for the
age I'm modelling at the moment. So - is it possible to alter the model so
the existing ground reaction forces are reduced to a reasonable percentage
of the applied scaled body weight during the gait cycle. Or do I need
reaction forces for the age I am trying to model for the inverse to work?
For later reference when we plan to obtain juvenile gait data - do the c3d
files have to obtained in a specific marker set up (I'm trying to use a 6
D.O.F. set up but it does integrate with the model)
Many thanks
Pete
--- On Tue, 17/3/09, AnyScript Support <anyscriptsup@
<mailto:anyscriptsup%40anybodytech.com> anybodytech.com> wrote:

From: AnyScript Support <anyscriptsup@
<mailto:anyscriptsup%40anybodytech.com> anybodytech.com>
Subject: RE: [AnyScript] GaitUniMiami
To: anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com
Date: Tuesday, 17 March, 2009, 2:23 PM

Hello Pete,

If you just scale the model it will not deliver the right results. What is
your approach for the ground reaction forces?

Best regards,

Sebastian

_____

From: anyscript@yahoogrou ps.com [mailto:anyscript@yahoogrou ps.com] On
Behalf
Of dc_pete
Sent: 16. marts 2009 14:22
To: anyscript@yahoogrou ps.com
Subject: [AnyScript] GaitUniMiami

Hi,
I'm trying to build a model of an 8 yr old during a gait cycle. As the gait
between this age and adult gait is not too different, I'm adapting the
GaitUniMiami model using scaling methods to adjust the model
anthropometrics.
I've have changed the scaling of the skeletal segments based upon a define
body weight and height, through altering the AnyMan.any file so the
AnthroSegmentLength s file is parameterised (so it is similar to that of the
scaling tutorial). Although the model rescales, the feet of the skeleton not
longer contact the force plate. The inverse dynamics still work and compute
muscle forces. Therefore, I wondered if the model should contact the ground,
or if this is just graphical and the muscle forces can be presumed accurate.

Many thanks
Pete

[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]

 

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 09:25 PM.