Center of Mass for forearm

Hello,
one problem is solved and now I´ve got a new one: When I look at the
forearm, the center of mass seems to be outside the segment. When I
include a reference frame at the coordinates of “sCOM” of the ulna, it
appears in the elbow joint and not in the middle (more or less) of the
forearm, even if I ran the kinematic analysis. Have I overlooked a
reference? I think it`s a problem if there are inertias but the CoM is
not at his natural place. Is there another place to define “sCOM” of a
segment, or are there references?
With best regards, Maren

Hi Maren

Which model is it you are working with? or could you zip it and upload it?

Regards Christian

Maren wrote:
>
> Hello,
> one problem is solved and now I´ve got a new one: When I look at the
> forearm, the center of mass seems to be outside the segment. When I
> include a reference frame at the coordinates of “sCOM” of the ulna, it
> appears in the elbow joint and not in the middle (more or less) of the
> forearm, even if I ran the kinematic analysis. Have I overlooked a
> reference? I think it`s a problem if there are inertias but the CoM is
> not at his natural place. Is there another place to define “sCOM” of a
> segment, or are there references?
> With best regards, Maren
>
>

Hi Christian,
I included the AnyDrawRefFrames on a wrog position in the file. They
showed the reference frame of the segment and not the Center of mass.
Now I´ve found the right place for AnyDrawRefFrame and they show a
realistic position for the CoM. So there is no problem any longer,
thank yuo very much, with best regards, Maren

— In anyscript@yahoogroups.com, Christian Gammelgaard <cgol03@…>
wrote:
>
> Hi Maren
>
> Which model is it you are working with? or could you zip it and
upload it?
>
> Regards Christian
>
> Maren wrote:
> >
> > Hello,
> > one problem is solved and now I´ve got a new one: When I look at the
> > forearm, the center of mass seems to be outside the segment. When I
> > include a reference frame at the coordinates of “sCOM” of the ulna, it
> > appears in the elbow joint and not in the middle (more or less) of the
> > forearm, even if I ran the kinematic analysis. Have I overlooked a
> > reference? I think it`s a problem if there are inertias but the CoM is
> > not at his natural place. Is there another place to define “sCOM” of a
> > segment, or are there references?
> > With best regards, Maren
> >
> >
>

Hi Maren

ok:D

Regards Christian

Maren wrote:
>
> Hi Christian,
> I included the AnyDrawRefFrames on a wrog position in the file. They
> showed the reference frame of the segment and not the Center of mass.
> Now I´ve found the right place for AnyDrawRefFrame and they show a
> realistic position for the CoM. So there is no problem any longer,
> thank yuo very much, with best regards, Maren
>
> — In anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>,
> Christian Gammelgaard <cgol03@…>
> wrote:
> >
> > Hi Maren
> >
> > Which model is it you are working with? or could you zip it and
> upload it?
> >
> > Regards Christian
> >
> > Maren wrote:
> > >
> > > Hello,
> > > one problem is solved and now I´ve got a new one: When I look at the
> > > forearm, the center of mass seems to be outside the segment. When I
> > > include a reference frame at the coordinates of “sCOM” of the ulna, it
> > > appears in the elbow joint and not in the middle (more or less) of the
> > > forearm, even if I ran the kinematic analysis. Have I overlooked a
> > > reference? I think it`s a problem if there are inertias but the CoM is
> > > not at his natural place. Is there another place to define “sCOM” of a
> > > segment, or are there references?
> > > With best regards, Maren
> > >
> > >
> >
>
>

Hello again, it`s my fault, I included the AnyDrawRefFrame on the
wrong place. I found the Center of Mass where it should be. Here I
don´t need help anymore. With best regards, Maren
>
>>