Segment Rotation Question

Hello everyone,

My name is Ceren. I am a master’s student at the Department of
Biomedical Engineering at RWTH Aachen. I am building models with the
AnyBody Modeling System as part of my thesis project. I have
encountered some problems and I was hoping that you could help me.

Currently, I am trying to build the model of a deformity by using
the StandingModel. The deformity is that one leg of the model is
shorter than the other leg. To have a realistic model, I need to
rotate the pelvis so that both feet are touching the ground. The
upper body, however, should be perpendicular to the ground, despite
the rotation of the pelvis. To acchieve this, I tried to rotate the
pelvis segment by changing the values of the
Mannequins.Posture.PelvisRotX/Y/Z variables, but the whole body
rotates along with the pelvis as if the joints are absolutely fixed.
Is there any way I can change the orientation of the pelvis without
changing the orientations of the other connecting segments.

I hope I was clear with my question.

Best wishes,
Ceren Saglamer

Hello Ceren,
I am a graduate student at UC Davis and have been learning the
StandingModel myself. I will attempt to answer your question; I had a
similar problem learning about those same variables.

The PelvisPos and PelvisRot parameters you are adjusting are for
loading puroposes only. The actual joint angles for analysis are
controlled further down in the file. Try changing some of the hip
parameters, for example, HipAbduction.

Brent Ulrey

— In anyscript@yahoogroups.com, “cerensaglamer” <ceren.saglamer@…>
wrote:
>
> Hello everyone,
>
> My name is Ceren. I am a master’s student at the Department of
> Biomedical Engineering at RWTH Aachen. I am building models with the
> AnyBody Modeling System as part of my thesis project. I have
> encountered some problems and I was hoping that you could help me.
>
> Currently, I am trying to build the model of a deformity by using
> the StandingModel. The deformity is that one leg of the model is
> shorter than the other leg. To have a realistic model, I need to
> rotate the pelvis so that both feet are touching the ground. The
> upper body, however, should be perpendicular to the ground, despite
> the rotation of the pelvis. To acchieve this, I tried to rotate the
> pelvis segment by changing the values of the
> Mannequins.Posture.PelvisRotX/Y/Z variables, but the whole body
> rotates along with the pelvis as if the joints are absolutely fixed.
> Is there any way I can change the orientation of the pelvis without
> changing the orientations of the other connecting segments.
>
> I hope I was clear with my question.
>
> Best wishes,
> Ceren Saglamer
>

Hello Brent,

Thank you for your help. I managed to build the model by changing
the HipAbduction, PelvisThoraxLateralBending and PelvisRot values.

Ceren

— In anyscript@yahoogroups.com, “blulrey” <blulrey@…> wrote:
>
> Hello Ceren,
> I am a graduate student at UC Davis and have been learning the
> StandingModel myself. I will attempt to answer your question; I
had a
> similar problem learning about those same variables.
>
> The PelvisPos and PelvisRot parameters you are adjusting are for
> loading puroposes only. The actual joint angles for analysis are
> controlled further down in the file. Try changing some of the hip
> parameters, for example, HipAbduction.
>
> Brent Ulrey
>
>
> — In anyscript@yahoogroups.com, “cerensaglamer” <ceren.saglamer@>
> wrote:
> >
> > Hello everyone,
> >
> > My name is Ceren. I am a master’s student at the Department of
> > Biomedical Engineering at RWTH Aachen. I am building models with
the
> > AnyBody Modeling System as part of my thesis project. I have
> > encountered some problems and I was hoping that you could help
me.
> >
> > Currently, I am trying to build the model of a deformity by
using
> > the StandingModel. The deformity is that one leg of the model is
> > shorter than the other leg. To have a realistic model, I need to
> > rotate the pelvis so that both feet are touching the ground. The
> > upper body, however, should be perpendicular to the ground,
despite
> > the rotation of the pelvis. To acchieve this, I tried to rotate
the
> > pelvis segment by changing the values of the
> > Mannequins.Posture.PelvisRotX/Y/Z variables, but the whole body
> > rotates along with the pelvis as if the joints are absolutely
fixed.
> > Is there any way I can change the orientation of the pelvis
without
> > changing the orientations of the other connecting segments.
> >
> > I hope I was clear with my question.
> >
> > Best wishes,
> > Ceren Saglamer
> >
>