I have a model to simulate lower extremity bracing in static
condition. Bracing forces and moment are applied on the foot
(GroundJoint) and the bracing posture is given. These information are
determined in the file “Mannequin”. However, when I run the
InverseDynamicAnalysis to calculate muscle forces, the hip always
adduct that makes the final hip angle not in the desired posture. All
the rotation at hip joint are constrained. Is there anything I missed
in the modeling? The model file is uploaded in the folder “braking
problem”. Thanks for your help.
I took a quick look at your model. I don’t see any difference in the
Hip adduction from the SetInitialConditions to the
InverseDynamicAnalysis? You can just change the adduction in the
Mannequin.any file. Maybe I misunderstand?
Best regards
Christian, AnyBody Support
— In anyscript@yahoogroups.com, “chiayuan_um” <chiayuan_um@…> wrote:
>
> Hi,
>
> I have a model to simulate lower extremity bracing in static
> condition. Bracing forces and moment are applied on the foot
> (GroundJoint) and the bracing posture is given. These information are
> determined in the file “Mannequin”. However, when I run the
> InverseDynamicAnalysis to calculate muscle forces, the hip always
> adduct that makes the final hip angle not in the desired posture. All
> the rotation at hip joint are constrained. Is there anything I missed
> in the modeling? The model file is uploaded in the folder “braking
> problem”. Thanks for your help.
>
> Regards,
>
> Mark
>
Thanks for your answer. I think I didn’t make my question clear.
The posture given in the Mannequin.any file is my target posture. When
I load model in the model view, the posture shows as what we give. For
example, if we look up from the bottom of the chair, two thighs are
parallel with the edges of the seat. However, when I run either
SetInitialConditions or InverseDynamicAnalysis, hip angle changes (two
knees are closer).
I am expecting the muscle force prediction is from the posture I set
in the Mannequin.any. Now, the results seems from the new posture. All
the joint movement at the lower extremity ate constrained. I am
wondering why does the posture change? How can I solve this problem?
Thanks for your time and help.
Mark
— In anyscript@yahoogroups.com, “AnyBody Support” <support@…> wrote:
>
> Hi Mark
>
> I took a quick look at your model. I don’t see any difference in the
> Hip adduction from the SetInitialConditions to the
> InverseDynamicAnalysis? You can just change the adduction in the
> Mannequin.any file. Maybe I misunderstand?
>
> Best regards
> Christian, AnyBody Support
>
>
> — In anyscript@yahoogroups.com, “chiayuan_um” <chiayuan_um@> wrote:
> >
> > Hi,
> >
> > I have a model to simulate lower extremity bracing in static
> > condition. Bracing forces and moment are applied on the foot
> > (GroundJoint) and the bracing posture is given. These information are
> > determined in the file “Mannequin”. However, when I run the
> > InverseDynamicAnalysis to calculate muscle forces, the hip always
> > adduct that makes the final hip angle not in the desired posture. All
> > the rotation at hip joint are constrained. Is there anything I missed
> > in the modeling? The model file is uploaded in the folder “braking
> > problem”. Thanks for your help.
> >
> > Regards,
> >
> > Mark
> >
>
The initial positions are the load time postions, these are not
accurate, since the model kinematics have not been solve yet.
When you run a kinematic analysis the load time positons are used as
the initial guess of the segments positons, nothing else. So in
principle these should just be good enough to let the model solve in
the correct way.
In all the repository model the initial positions are calculated
using the joints angles from the mannequin.any file. If you look into
the initialposition.any file you will see a lot of equations. This is
basically a “hardcoded” remake of the real models kinematics. In
previous versions you had to give the rotataion matrix for each
segment. For models like FreePosture the load time positons and the
positions after having solved the kinematics will be almost
identical, because they are driven in the same way. As soons as you
apply any other drivers to the model than this, there will not be a
perfect macth between the positions. This is not a problem as long as
the mannequin values are good enough to make the model assemble
correctly.
So to summarize, it the positions you have after having solved the
kinematics that counts, the intial ones should just be close enough.
Except from that they have no influence on the model.
Best regards,
Søren AnyBody Support
— In anyscript@yahoogroups.com, “chiayuan_um” <chiayuan_um@…>
wrote:
>
> Hi Christian,
>
> Thanks for your answer. I think I didn’t make my question clear.
>
> The posture given in the Mannequin.any file is my target posture.
When
> I load model in the model view, the posture shows as what we give.
For
> example, if we look up from the bottom of the chair, two thighs are
> parallel with the edges of the seat. However, when I run either
> SetInitialConditions or InverseDynamicAnalysis, hip angle changes
(two
> knees are closer).
>
> I am expecting the muscle force prediction is from the posture I set
> in the Mannequin.any. Now, the results seems from the new posture.
All
> the joint movement at the lower extremity ate constrained. I am
> wondering why does the posture change? How can I solve this problem?
>
> Thanks for your time and help.
>
> Mark
>
>
> — In anyscript@yahoogroups.com, “AnyBody Support” <support@>
wrote:
> >
> > Hi Mark
> >
> > I took a quick look at your model. I don’t see any difference in
the
> > Hip adduction from the SetInitialConditions to the
> > InverseDynamicAnalysis? You can just change the adduction in the
> > Mannequin.any file. Maybe I misunderstand?
> >
> > Best regards
> > Christian, AnyBody Support
> >
> >
> > — In anyscript@yahoogroups.com, “chiayuan_um” <chiayuan_um@>
wrote:
> > >
> > > Hi,
> > >
> > > I have a model to simulate lower extremity bracing in static
> > > condition. Bracing forces and moment are applied on the foot
> > > (GroundJoint) and the bracing posture is given. These
information are
> > > determined in the file “Mannequin”. However, when I run the
> > > InverseDynamicAnalysis to calculate muscle forces, the hip
always
> > > adduct that makes the final hip angle not in the desired
posture. All
> > > the rotation at hip joint are constrained. Is there anything I
missed
> > > in the modeling? The model file is uploaded in the
folder “braking
> > > problem”. Thanks for your help.
> > >
> > > Regards,
> > >
> > > Mark
> > >
> >
>
— In anyscript@yahoogroups.com, “AnyBody Support” <support@…> wrote:
>
> Hi Mark
>
> The initial positions are the load time postions, these are not
> accurate, since the model kinematics have not been solve yet.
>
> When you run a kinematic analysis the load time positons are used as
> the initial guess of the segments positons, nothing else. So in
> principle these should just be good enough to let the model solve in
> the correct way.
>
> In all the repository model the initial positions are calculated
> using the joints angles from the mannequin.any file. If you look into
> the initialposition.any file you will see a lot of equations. This is
> basically a “hardcoded” remake of the real models kinematics. In
> previous versions you had to give the rotataion matrix for each
> segment. For models like FreePosture the load time positons and the
> positions after having solved the kinematics will be almost
> identical, because they are driven in the same way. As soons as you
> apply any other drivers to the model than this, there will not be a
> perfect macth between the positions. This is not a problem as long as
> the mannequin values are good enough to make the model assemble
> correctly.
>
> So to summarize, it the positions you have after having solved the
> kinematics that counts, the intial ones should just be close enough.
> Except from that they have no influence on the model.
>
> Best regards,
> Søren AnyBody Support
>
> — In anyscript@yahoogroups.com, “chiayuan_um” <chiayuan_um@>
> wrote:
> >
> > Hi Christian,
> >
> > Thanks for your answer. I think I didn’t make my question clear.
> >
> > The posture given in the Mannequin.any file is my target posture.
> When
> > I load model in the model view, the posture shows as what we give.
> For
> > example, if we look up from the bottom of the chair, two thighs are
> > parallel with the edges of the seat. However, when I run either
> > SetInitialConditions or InverseDynamicAnalysis, hip angle changes
> (two
> > knees are closer).
> >
> > I am expecting the muscle force prediction is from the posture I set
> > in the Mannequin.any. Now, the results seems from the new posture.
> All
> > the joint movement at the lower extremity ate constrained. I am
> > wondering why does the posture change? How can I solve this problem?
> >
> > Thanks for your time and help.
> >
> > Mark
> >
> >
> > — In anyscript@yahoogroups.com, “AnyBody Support” <support@>
> wrote:
> > >
> > > Hi Mark
> > >
> > > I took a quick look at your model. I don’t see any difference in
> the
> > > Hip adduction from the SetInitialConditions to the
> > > InverseDynamicAnalysis? You can just change the adduction in the
> > > Mannequin.any file. Maybe I misunderstand?
> > >
> > > Best regards
> > > Christian, AnyBody Support
> > >
> > >
> > > — In anyscript@yahoogroups.com, “chiayuan_um” <chiayuan_um@>
> wrote:
> > > >
> > > > Hi,
> > > >
> > > > I have a model to simulate lower extremity bracing in static
> > > > condition. Bracing forces and moment are applied on the foot
> > > > (GroundJoint) and the bracing posture is given. These
> information are
> > > > determined in the file “Mannequin”. However, when I run the
> > > > InverseDynamicAnalysis to calculate muscle forces, the hip
> always
> > > > adduct that makes the final hip angle not in the desired
> posture. All
> > > > the rotation at hip joint are constrained. Is there anything I
> missed
> > > > in the modeling? The model file is uploaded in the
> folder “braking
> > > > problem”. Thanks for your help.
> > > >
> > > > Regards,
> > > >
> > > > Mark
> > > >
> > >
> >
>