# Muscle models two elements linear

Hi guys,
I’m working on muscle models of Anybody and I try to explain
how they work for an abduction of the arm as an example. For the
simple model, I’ve no problem. However, for the two elements linear
model (2Elin), I have difficulties to find a reasonable value for ‘V0’
parameter for the deltoid muscle. There is not a lot of litterature
for this model. From what I know, the lateral part of the deltoid is
responsible for the abduction and it is composed mostly of slow twitch
fibres. Can i put a high value of ‘V0’ because of that ? I mean, if
this part of the muscle is composed of slow twitch fibres, does it
make it not sensitive to contraction velocity ? I’m not very sure to
understand well this parameter.

Thank you for you help

Pierre

Hi Pierre-Olivier,

Fast twitch fibers are fast and slow twitch fibers are slow. So if
the lateral deltoid mostly has slow twitch fibers then it is likely
to be MORE sensible to velocity and you should consequently use a LOW
value of V0. Remember, V0 is the velocity at which the muscle
completely loses its strength.

Have you considered using the three-element muscle mudel instead? It
allows you to input fiber length and the ratio of fast to slow twitch
fibers, and you do not have to worry about what V0 is. The muscle
model works that out automatically.

Best regards,
John

— In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
<pothekid@…> wrote:
>
> Hi guys,
> I’m working on muscle models of Anybody and I try to explain
> how they work for an abduction of the arm as an example. For the
> simple model, I’ve no problem. However, for the two elements linear
> model (2Elin), I have difficulties to find a reasonable value
for ‘V0’
> parameter for the deltoid muscle. There is not a lot of litterature
> for this model. From what I know, the lateral part of the deltoid is
> responsible for the abduction and it is composed mostly of slow
twitch
> fibres. Can i put a high value of ‘V0’ because of that ? I mean, if
> this part of the muscle is composed of slow twitch fibres, does it
> make it not sensitive to contraction velocity ? I’m not very sure to
> understand well this parameter.
>
> Thank you for you help
>
> Pierre
>

Hi John,
thank you for your advices. Yes, eventually I will come to the
3-elements model soon, but before I have to review the 2 elements to
prove that its not sufficient for what I need. Also, my supervisors
asked me to explain them the way that these models works. At the same
time, it allow me to know a little bit more about the software.

I saw that in the tutorial, they put a minimal value of -0.3 m/s for
the V0 parameter, is it a good value to use for the deltoid muscle for
instance ? In my model, the velocity is very reduced and I think that
it would not have any effect on the strength of the muscle, but I
still want to know what is the limit of contraction velocity for the
muscle. If you don’t know, it’s ok, I will find a estimated value by
doing some tests.

For the slow and fast twitch, it seems to have some differences
between the divisions of the deltoid muscle, from the new study of
Gorelick and Brown (2007). However, the ‘Fcfast’ of all the divisions
in AnyBody are set to 40%. Maybe it should have some improvement to

Here is the complete reference, if you didn’t read it already :

Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic assessment of
contractile properties within seven segments of the human deltoid
muscle Â». European Journal of Applied Physiology, vol. 100, no 1, p.
35-44.

Thank you for your support and have a great summer.

Pierre

— In anyscript@yahoogroups.com, “John Rasmussen” <jr@…> wrote:
>
> Hi Pierre-Olivier,
>
> Fast twitch fibers are fast and slow twitch fibers are slow. So if
> the lateral deltoid mostly has slow twitch fibers then it is likely
> to be MORE sensible to velocity and you should consequently use a LOW
> value of V0. Remember, V0 is the velocity at which the muscle
> completely loses its strength.
>
> Have you considered using the three-element muscle mudel instead? It
> allows you to input fiber length and the ratio of fast to slow twitch
> fibers, and you do not have to worry about what V0 is. The muscle
> model works that out automatically.
>
> Best regards,
> John
>
>
> — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> <pothekid@> wrote:
> >
> > Hi guys,
> > I’m working on muscle models of Anybody and I try to explain
> > how they work for an abduction of the arm as an example. For the
> > simple model, I’ve no problem. However, for the two elements linear
> > model (2Elin), I have difficulties to find a reasonable value
> for ‘V0’
> > parameter for the deltoid muscle. There is not a lot of litterature
> > for this model. From what I know, the lateral part of the deltoid is
> > responsible for the abduction and it is composed mostly of slow
> twitch
> > fibres. Can i put a high value of ‘V0’ because of that ? I mean, if
> > this part of the muscle is composed of slow twitch fibres, does it
> > make it not sensitive to contraction velocity ? I’m not very sure to
> > understand well this parameter.
> >
> > Thank you for you help
> >
> > Pierre
> >
>

Hi guys,
I’ve an other question regarding the muscle models. What is the
muscle’s neutral position ? I know that it is related to the
calibration and I know that at this position, the muscle has is
optimal strength, but does it means that’s because it does not develop
any force ? What about the calibration, do I need to do it for the
“two elements model” also ?

Thank you for the support.

Pierre

— In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
<pothekid@…> wrote:
>
> Hi John,
> thank you for your advices. Yes, eventually I will come to the
> 3-elements model soon, but before I have to review the 2 elements to
> prove that its not sufficient for what I need. Also, my supervisors
> asked me to explain them the way that these models works. At the same
> time, it allow me to know a little bit more about the software.
>
> I saw that in the tutorial, they put a minimal value of -0.3 m/s for
> the V0 parameter, is it a good value to use for the deltoid muscle for
> instance ? In my model, the velocity is very reduced and I think that
> it would not have any effect on the strength of the muscle, but I
> still want to know what is the limit of contraction velocity for the
> muscle. If you don’t know, it’s ok, I will find a estimated value by
> doing some tests.
>
> For the slow and fast twitch, it seems to have some differences
> between the divisions of the deltoid muscle, from the new study of
> Gorelick and Brown (2007). However, the ‘Fcfast’ of all the divisions
> in AnyBody are set to 40%. Maybe it should have some improvement to
> the model by considering this article.
>
> Here is the complete reference, if you didn’t read it already :
>
> Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic assessment of
> contractile properties within seven segments of the human deltoid
> muscle Â». European Journal of Applied Physiology, vol. 100, no 1, p.
> 35-44.
>
> Thank you for your support and have a great summer.
>
> Pierre
>
> — In anyscript@yahoogroups.com, “John Rasmussen” <jr@> wrote:
> >
> > Hi Pierre-Olivier,
> >
> > Fast twitch fibers are fast and slow twitch fibers are slow. So if
> > the lateral deltoid mostly has slow twitch fibers then it is likely
> > to be MORE sensible to velocity and you should consequently use a LOW
> > value of V0. Remember, V0 is the velocity at which the muscle
> > completely loses its strength.
> >
> > Have you considered using the three-element muscle mudel instead? It
> > allows you to input fiber length and the ratio of fast to slow twitch
> > fibers, and you do not have to worry about what V0 is. The muscle
> > model works that out automatically.
> >
> > Best regards,
> > John
> >
> >
> > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > <pothekid@> wrote:
> > >
> > > Hi guys,
> > > I’m working on muscle models of Anybody and I try to explain
> > > how they work for an abduction of the arm as an example. For the
> > > simple model, I’ve no problem. However, for the two elements linear
> > > model (2Elin), I have difficulties to find a reasonable value
> > for ‘V0’
> > > parameter for the deltoid muscle. There is not a lot of litterature
> > > for this model. From what I know, the lateral part of the deltoid is
> > > responsible for the abduction and it is composed mostly of slow
> > twitch
> > > fibres. Can i put a high value of ‘V0’ because of that ? I mean, if
> > > this part of the muscle is composed of slow twitch fibres, does it
> > > make it not sensitive to contraction velocity ? I’m not very sure to
> > > understand well this parameter.
> > >
> > > Thank you for you help
> > >
> > > Pierre
> > >
> >
>

Hi Pierre Olivier,

As you understood, the muscle’s neutral position is the position (for
a certain movement) where the muscle has is optimal strength. That
mean at this position the muscle is able to provide his maximum force
F0. This position is typically the one where you need the more your
muscle during the movement. For example if you lift some weight with
your arm using your biceps, you will feel the position you are
stronger is for an elbow flexion of approximately 90 degrees. This is
where your biceps has his optimal strength. We use this assumption
for the calibration. You may see the calibration sequence drive the
body in different positions, they are chosen so that for each
position a set of muscle is in the position where they are supposed
to be the strongest.

The aim of the calibration is to adjust the tendon length so that the
muscle (the contractile element) has is optimal length (corresponding
to his optimal strength) at the neutral position explained above. The
two elements model also takes into account the tendon length and the
contractile element length. So the problem is the same as for the
three elements model: unless you already know the appropriate tendon
length, you should run a calibration sequence. If you don’t run it
you take the risk to get over stretched muscles without strength.

Best regards,
Sylvain, AnyBody Support.

— In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
<pothekid@…> wrote:
>
> Hi guys,
> I’ve an other question regarding the muscle models. What is
the
> muscle’s neutral position ? I know that it is related to the
> calibration and I know that at this position, the muscle has is
> optimal strength, but does it means that’s because it does not
develop
> any force ? What about the calibration, do I need to do it for the
> “two elements model” also ?
>
> Thank you for the support.
>
> Pierre
>
> — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> <pothekid@> wrote:
> >
> > Hi John,
> > thank you for your advices. Yes, eventually I will come to
the
> > 3-elements model soon, but before I have to review the 2 elements
to
> > prove that its not sufficient for what I need. Also, my
supervisors
> > asked me to explain them the way that these models works. At the
same
> > time, it allow me to know a little bit more about the software.
> >
> > I saw that in the tutorial, they put a minimal value of -0.3 m/s
for
> > the V0 parameter, is it a good value to use for the deltoid
muscle for
> > instance ? In my model, the velocity is very reduced and I think
that
> > it would not have any effect on the strength of the muscle, but I
> > still want to know what is the limit of contraction velocity for
the
> > muscle. If you don’t know, it’s ok, I will find a estimated value
by
> > doing some tests.
> >
> > For the slow and fast twitch, it seems to have some differences
> > between the divisions of the deltoid muscle, from the new study of
> > Gorelick and Brown (2007). However, the ‘Fcfast’ of all the
divisions
> > in AnyBody are set to 40%. Maybe it should have some improvement
to
> > the model by considering this article.
> >
> > Here is the complete reference, if you didn’t read it already :
> >
> > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic assessment of
> > contractile properties within seven segments of the human deltoid
> > muscle Â». European Journal of Applied Physiology, vol. 100, no 1,
p.
> > 35-44.
> >
> > Thank you for your support and have a great summer.
> >
> > Pierre
> >
> > — In anyscript@yahoogroups.com, “John Rasmussen” <jr@> wrote:
> > >
> > > Hi Pierre-Olivier,
> > >
> > > Fast twitch fibers are fast and slow twitch fibers are slow. So
if
> > > the lateral deltoid mostly has slow twitch fibers then it is
likely
> > > to be MORE sensible to velocity and you should consequently use
a LOW
> > > value of V0. Remember, V0 is the velocity at which the muscle
> > > completely loses its strength.
> > >
> > > Have you considered using the three-element muscle mudel
> > > allows you to input fiber length and the ratio of fast to slow
twitch
> > > fibers, and you do not have to worry about what V0 is. The
muscle
> > > model works that out automatically.
> > >
> > > Best regards,
> > > John
> > >
> > >
> > > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > > <pothekid@> wrote:
> > > >
> > > > Hi guys,
> > > > I’m working on muscle models of Anybody and I try to
explain
> > > > how they work for an abduction of the arm as an example. For
the
> > > > simple model, I’ve no problem. However, for the two elements
linear
> > > > model (2Elin), I have difficulties to find a reasonable value
> > > for ‘V0’
> > > > parameter for the deltoid muscle. There is not a lot of
litterature
> > > > for this model. From what I know, the lateral part of the
deltoid is
> > > > responsible for the abduction and it is composed mostly of
slow
> > > twitch
> > > > fibres. Can i put a high value of ‘V0’ because of that ? I
mean, if
> > > > this part of the muscle is composed of slow twitch fibres,
does it
> > > > make it not sensitive to contraction velocity ? I’m not very
sure to
> > > > understand well this parameter.
> > > >
> > > > Thank you for you help
> > > >
> > > > Pierre
> > > >
> > >
> >
>

Hi guys,
thank you for you help. I did the calibration for the two
muscle models (2E lin & 3E). However, I’ve seen that in the 3D model
of the upper arm, the calibration is done with a 10 degrees abduction
for the scapular deltoid. I consider that the mean deltoid is
representative of the abduction in the plane of the scapula. Thus, do
you think that I can use the same value for my 2D model calibration ?

I’ve found added information about the muscle models on the new
updated tutorials. Before, I was working with the 2006 versions.

Thank you again

Pierre

— In anyscript@yahoogroups.com, “AnyBody Support” <support@…> wrote:
>
> Hi Pierre Olivier,
>
> As you understood, the muscle’s neutral position is the position (for
> a certain movement) where the muscle has is optimal strength. That
> mean at this position the muscle is able to provide his maximum force
> F0. This position is typically the one where you need the more your
> muscle during the movement. For example if you lift some weight with
> your arm using your biceps, you will feel the position you are
> stronger is for an elbow flexion of approximately 90 degrees. This is
> where your biceps has his optimal strength. We use this assumption
> for the calibration. You may see the calibration sequence drive the
> body in different positions, they are chosen so that for each
> position a set of muscle is in the position where they are supposed
> to be the strongest.
>
> The aim of the calibration is to adjust the tendon length so that the
> muscle (the contractile element) has is optimal length (corresponding
> to his optimal strength) at the neutral position explained above. The
> two elements model also takes into account the tendon length and the
> contractile element length. So the problem is the same as for the
> three elements model: unless you already know the appropriate tendon
> length, you should run a calibration sequence. If you don’t run it
> you take the risk to get over stretched muscles without strength.
>
> Best regards,
> Sylvain, AnyBody Support.
>
>
>
>
> — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> <pothekid@> wrote:
> >
> > Hi guys,
> > I’ve an other question regarding the muscle models. What is
> the
> > muscle’s neutral position ? I know that it is related to the
> > calibration and I know that at this position, the muscle has is
> > optimal strength, but does it means that’s because it does not
> develop
> > any force ? What about the calibration, do I need to do it for the
> > “two elements model” also ?
> >
> > Thank you for the support.
> >
> > Pierre
> >
> > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > <pothekid@> wrote:
> > >
> > > Hi John,
> > > thank you for your advices. Yes, eventually I will come to
> the
> > > 3-elements model soon, but before I have to review the 2 elements
> to
> > > prove that its not sufficient for what I need. Also, my
> supervisors
> > > asked me to explain them the way that these models works. At the
> same
> > > time, it allow me to know a little bit more about the software.
> > >
> > > I saw that in the tutorial, they put a minimal value of -0.3 m/s
> for
> > > the V0 parameter, is it a good value to use for the deltoid
> muscle for
> > > instance ? In my model, the velocity is very reduced and I think
> that
> > > it would not have any effect on the strength of the muscle, but I
> > > still want to know what is the limit of contraction velocity for
> the
> > > muscle. If you don’t know, it’s ok, I will find a estimated value
> by
> > > doing some tests.
> > >
> > > For the slow and fast twitch, it seems to have some differences
> > > between the divisions of the deltoid muscle, from the new study of
> > > Gorelick and Brown (2007). However, the ‘Fcfast’ of all the
> divisions
> > > in AnyBody are set to 40%. Maybe it should have some improvement
> to
> > > the model by considering this article.
> > >
> > > Here is the complete reference, if you didn’t read it already :
> > >
> > > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic assessment of
> > > contractile properties within seven segments of the human deltoid
> > > muscle Â». European Journal of Applied Physiology, vol. 100, no 1,
> p.
> > > 35-44.
> > >
> > > Thank you for your support and have a great summer.
> > >
> > > Pierre
> > >
> > > — In anyscript@yahoogroups.com, “John Rasmussen” <jr@> wrote:
> > > >
> > > > Hi Pierre-Olivier,
> > > >
> > > > Fast twitch fibers are fast and slow twitch fibers are slow. So
> if
> > > > the lateral deltoid mostly has slow twitch fibers then it is
> likely
> > > > to be MORE sensible to velocity and you should consequently use
> a LOW
> > > > value of V0. Remember, V0 is the velocity at which the muscle
> > > > completely loses its strength.
> > > >
> > > > Have you considered using the three-element muscle mudel
> > > > allows you to input fiber length and the ratio of fast to slow
> twitch
> > > > fibers, and you do not have to worry about what V0 is. The
> muscle
> > > > model works that out automatically.
> > > >
> > > > Best regards,
> > > > John
> > > >
> > > >
> > > > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > > > <pothekid@> wrote:
> > > > >
> > > > > Hi guys,
> > > > > I’m working on muscle models of Anybody and I try to
> explain
> > > > > how they work for an abduction of the arm as an example. For
> the
> > > > > simple model, I’ve no problem. However, for the two elements
> linear
> > > > > model (2Elin), I have difficulties to find a reasonable value
> > > > for ‘V0’
> > > > > parameter for the deltoid muscle. There is not a lot of
> litterature
> > > > > for this model. From what I know, the lateral part of the
> deltoid is
> > > > > responsible for the abduction and it is composed mostly of
> slow
> > > > twitch
> > > > > fibres. Can i put a high value of ‘V0’ because of that ? I
> mean, if
> > > > > this part of the muscle is composed of slow twitch fibres,
> does it
> > > > > make it not sensitive to contraction velocity ? I’m not very
> sure to
> > > > > understand well this parameter.
> > > > >
> > > > > Thank you for you help
> > > > >
> > > > > Pierre
> > > > >
> > > >
> > >
> >
>

Hi,

Yes it sounds reasonable. I understand your 2D model is in the plane
of the scapula. I think you can use the same value for the deltoid in
the 2D model.
It is a good idea to look at the tutorials, lot of things are well
explained there.

Best regards,
Sylvain, AnyBody Support.

— In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
<pothekid@…> wrote:
>
> Hi guys,
> thank you for you help. I did the calibration for the two
> muscle models (2E lin & 3E). However, I’ve seen that in the 3D model
> of the upper arm, the calibration is done with a 10 degrees
abduction
> for the scapular deltoid. I consider that the mean deltoid is
> representative of the abduction in the plane of the scapula. Thus,
do
> you think that I can use the same value for my 2D model
calibration ?
>
> I’ve found added information about the muscle models on the new
> updated tutorials. Before, I was working with the 2006 versions.
>
> Thank you again
>
> Pierre
>
>
> — In anyscript@yahoogroups.com, “AnyBody Support” <support@>
wrote:
> >
> > Hi Pierre Olivier,
> >
> > As you understood, the muscle’s neutral position is the position
(for
> > a certain movement) where the muscle has is optimal strength.
That
> > mean at this position the muscle is able to provide his maximum
force
> > F0. This position is typically the one where you need the more
your
> > muscle during the movement. For example if you lift some weight
with
> > your arm using your biceps, you will feel the position you are
> > stronger is for an elbow flexion of approximately 90 degrees.
This is
> > where your biceps has his optimal strength. We use this
assumption
> > for the calibration. You may see the calibration sequence drive
the
> > body in different positions, they are chosen so that for each
> > position a set of muscle is in the position where they are
supposed
> > to be the strongest.
> >
> > The aim of the calibration is to adjust the tendon length so that
the
> > muscle (the contractile element) has is optimal length
(corresponding
> > to his optimal strength) at the neutral position explained above.
The
> > two elements model also takes into account the tendon length and
the
> > contractile element length. So the problem is the same as for the
> > three elements model: unless you already know the appropriate
tendon
> > length, you should run a calibration sequence. If you don’t run
it
> > you take the risk to get over stretched muscles without strength.
> >
> > Best regards,
> > Sylvain, AnyBody Support.
> >
> >
> >
> >
> > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > <pothekid@> wrote:
> > >
> > > Hi guys,
> > > I’ve an other question regarding the muscle models. What
is
> > the
> > > muscle’s neutral position ? I know that it is related to the
> > > calibration and I know that at this position, the muscle has is
> > > optimal strength, but does it means that’s because it does not
> > develop
> > > any force ? What about the calibration, do I need to do it for
the
> > > “two elements model” also ?
> > >
> > > Thank you for the support.
> > >
> > > Pierre
> > >
> > > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > > <pothekid@> wrote:
> > > >
> > > > Hi John,
> > > > thank you for your advices. Yes, eventually I will
come to
> > the
> > > > 3-elements model soon, but before I have to review the 2
elements
> > to
> > > > prove that its not sufficient for what I need. Also, my
> > supervisors
> > > > asked me to explain them the way that these models works. At
the
> > same
> > > > time, it allow me to know a little bit more about the
software.
> > > >
> > > > I saw that in the tutorial, they put a minimal value of -0.3
m/s
> > for
> > > > the V0 parameter, is it a good value to use for the deltoid
> > muscle for
> > > > instance ? In my model, the velocity is very reduced and I
think
> > that
> > > > it would not have any effect on the strength of the muscle,
but I
> > > > still want to know what is the limit of contraction velocity
for
> > the
> > > > muscle. If you don’t know, it’s ok, I will find a estimated
value
> > by
> > > > doing some tests.
> > > >
> > > > For the slow and fast twitch, it seems to have some
differences
> > > > between the divisions of the deltoid muscle, from the new
study of
> > > > Gorelick and Brown (2007). However, the ‘Fcfast’ of all the
> > divisions
> > > > in AnyBody are set to 40%. Maybe it should have some
improvement
> > to
> > > > the model by considering this article.
> > > >
> > > > Here is the complete reference, if you didn’t read it
> > > >
> > > > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic
assessment of
> > > > contractile properties within seven segments of the human
deltoid
> > > > muscle Â». European Journal of Applied Physiology, vol. 100,
no 1,
> > p.
> > > > 35-44.
> > > >
> > > > Thank you for your support and have a great summer.
> > > >
> > > > Pierre
> > > >
> > > > — In anyscript@yahoogroups.com, “John Rasmussen” <jr@>
wrote:
> > > > >
> > > > > Hi Pierre-Olivier,
> > > > >
> > > > > Fast twitch fibers are fast and slow twitch fibers are
slow. So
> > if
> > > > > the lateral deltoid mostly has slow twitch fibers then it
is
> > likely
> > > > > to be MORE sensible to velocity and you should consequently
use
> > a LOW
> > > > > value of V0. Remember, V0 is the velocity at which the
muscle
> > > > > completely loses its strength.
> > > > >
> > > > > Have you considered using the three-element muscle mudel
> > instead? It
> > > > > allows you to input fiber length and the ratio of fast to
slow
> > twitch
> > > > > fibers, and you do not have to worry about what V0 is. The
> > muscle
> > > > > model works that out automatically.
> > > > >
> > > > > Best regards,
> > > > > John
> > > > >
> > > > >
> > > > > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > > > > <pothekid@> wrote:
> > > > > >
> > > > > > Hi guys,
> > > > > > I’m working on muscle models of Anybody and I try
to
> > explain
> > > > > > how they work for an abduction of the arm as an example.
For
> > the
> > > > > > simple model, I’ve no problem. However, for the two
elements
> > linear
> > > > > > model (2Elin), I have difficulties to find a reasonable
value
> > > > > for ‘V0’
> > > > > > parameter for the deltoid muscle. There is not a lot of
> > litterature
> > > > > > for this model. From what I know, the lateral part of the
> > deltoid is
> > > > > > responsible for the abduction and it is composed mostly
of
> > slow
> > > > > twitch
> > > > > > fibres. Can i put a high value of ‘V0’ because of that ?
I
> > mean, if
> > > > > > this part of the muscle is composed of slow twitch
fibres,
> > does it
> > > > > > make it not sensitive to contraction velocity ? I’m not
very
> > sure to
> > > > > > understand well this parameter.
> > > > > >
> > > > > > Thank you for you help
> > > > > >
> > > > > > Pierre
> > > > > >
> > > > >
> > > >
> > >
> >
>

Hi guys,
I try to use a new muscle model. Here is the way that I write
it in Matlab :

f0 = 819;

lo = lm(1); % the initial length of the muscle

eps = (lm - lo)/lo; % deformation of the muscle

Sm = f0*exp(-((eps+1).^(-0.4129)-1).^2/(0.105981));

I want to know hot to write it in AnyBody. I checked the exemple
'UserDefinedMuscle.any ', but I think that it’s not exactly what I
need to know.

I have an other question. Can it be possible to know the exact
formulas of the 3 element type model that you propose? I’ve found what
I believe to be the V0 formula for this model and it gives me :

V0 = -Lfbar*(K1 + K2*Fcfast)

But I’m still not sure about the rest of the formulas.

Thank you for your support.

Pierre

— In anyscript@yahoogroups.com, “AnyBody Support” <support@…> wrote:
>
> Hi,
>
> Yes it sounds reasonable. I understand your 2D model is in the plane
> of the scapula. I think you can use the same value for the deltoid in
> the 2D model.
> It is a good idea to look at the tutorials, lot of things are well
> explained there.
>
> Best regards,
> Sylvain, AnyBody Support.
>
>
>
>
> — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> <pothekid@> wrote:
> >
> > Hi guys,
> > thank you for you help. I did the calibration for the two
> > muscle models (2E lin & 3E). However, I’ve seen that in the 3D model
> > of the upper arm, the calibration is done with a 10 degrees
> abduction
> > for the scapular deltoid. I consider that the mean deltoid is
> > representative of the abduction in the plane of the scapula. Thus,
> do
> > you think that I can use the same value for my 2D model
> calibration ?
> >
> > I’ve found added information about the muscle models on the new
> > updated tutorials. Before, I was working with the 2006 versions.
> >
> > Thank you again
> >
> > Pierre
> >
> >
> > — In anyscript@yahoogroups.com, “AnyBody Support” <support@>
> wrote:
> > >
> > > Hi Pierre Olivier,
> > >
> > > As you understood, the muscle’s neutral position is the position
> (for
> > > a certain movement) where the muscle has is optimal strength.
> That
> > > mean at this position the muscle is able to provide his maximum
> force
> > > F0. This position is typically the one where you need the more
> your
> > > muscle during the movement. For example if you lift some weight
> with
> > > your arm using your biceps, you will feel the position you are
> > > stronger is for an elbow flexion of approximately 90 degrees.
> This is
> > > where your biceps has his optimal strength. We use this
> assumption
> > > for the calibration. You may see the calibration sequence drive
> the
> > > body in different positions, they are chosen so that for each
> > > position a set of muscle is in the position where they are
> supposed
> > > to be the strongest.
> > >
> > > The aim of the calibration is to adjust the tendon length so that
> the
> > > muscle (the contractile element) has is optimal length
> (corresponding
> > > to his optimal strength) at the neutral position explained above.
> The
> > > two elements model also takes into account the tendon length and
> the
> > > contractile element length. So the problem is the same as for the
> > > three elements model: unless you already know the appropriate
> tendon
> > > length, you should run a calibration sequence. If you don’t run
> it
> > > you take the risk to get over stretched muscles without strength.
> > >
> > > Best regards,
> > > Sylvain, AnyBody Support.
> > >
> > >
> > >
> > >
> > > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > > <pothekid@> wrote:
> > > >
> > > > Hi guys,
> > > > I’ve an other question regarding the muscle models. What
> is
> > > the
> > > > muscle’s neutral position ? I know that it is related to the
> > > > calibration and I know that at this position, the muscle has is
> > > > optimal strength, but does it means that’s because it does not
> > > develop
> > > > any force ? What about the calibration, do I need to do it for
> the
> > > > “two elements model” also ?
> > > >
> > > > Thank you for the support.
> > > >
> > > > Pierre
> > > >
> > > > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > > > <pothekid@> wrote:
> > > > >
> > > > > Hi John,
> > > > > thank you for your advices. Yes, eventually I will
> come to
> > > the
> > > > > 3-elements model soon, but before I have to review the 2
> elements
> > > to
> > > > > prove that its not sufficient for what I need. Also, my
> > > supervisors
> > > > > asked me to explain them the way that these models works. At
> the
> > > same
> > > > > time, it allow me to know a little bit more about the
> software.
> > > > >
> > > > > I saw that in the tutorial, they put a minimal value of -0.3
> m/s
> > > for
> > > > > the V0 parameter, is it a good value to use for the deltoid
> > > muscle for
> > > > > instance ? In my model, the velocity is very reduced and I
> think
> > > that
> > > > > it would not have any effect on the strength of the muscle,
> but I
> > > > > still want to know what is the limit of contraction velocity
> for
> > > the
> > > > > muscle. If you don’t know, it’s ok, I will find a estimated
> value
> > > by
> > > > > doing some tests.
> > > > >
> > > > > For the slow and fast twitch, it seems to have some
> differences
> > > > > between the divisions of the deltoid muscle, from the new
> study of
> > > > > Gorelick and Brown (2007). However, the ‘Fcfast’ of all the
> > > divisions
> > > > > in AnyBody are set to 40%. Maybe it should have some
> improvement
> > > to
> > > > > the model by considering this article.
> > > > >
> > > > > Here is the complete reference, if you didn’t read it
> > > > >
> > > > > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic
> assessment of
> > > > > contractile properties within seven segments of the human
> deltoid
> > > > > muscle Â». European Journal of Applied Physiology, vol. 100,
> no 1,
> > > p.
> > > > > 35-44.
> > > > >
> > > > > Thank you for your support and have a great summer.
> > > > >
> > > > > Pierre
> > > > >
> > > > > — In anyscript@yahoogroups.com, “John Rasmussen” <jr@>
> wrote:
> > > > > >
> > > > > > Hi Pierre-Olivier,
> > > > > >
> > > > > > Fast twitch fibers are fast and slow twitch fibers are
> slow. So
> > > if
> > > > > > the lateral deltoid mostly has slow twitch fibers then it
> is
> > > likely
> > > > > > to be MORE sensible to velocity and you should consequently
> use
> > > a LOW
> > > > > > value of V0. Remember, V0 is the velocity at which the
> muscle
> > > > > > completely loses its strength.
> > > > > >
> > > > > > Have you considered using the three-element muscle mudel
> > > instead? It
> > > > > > allows you to input fiber length and the ratio of fast to
> slow
> > > twitch
> > > > > > fibers, and you do not have to worry about what V0 is. The
> > > muscle
> > > > > > model works that out automatically.
> > > > > >
> > > > > > Best regards,
> > > > > > John
> > > > > >
> > > > > >
> > > > > > — In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
> > > > > > <pothekid@> wrote:
> > > > > > >
> > > > > > > Hi guys,
> > > > > > > I’m working on muscle models of Anybody and I try
> to
> > > explain
> > > > > > > how they work for an abduction of the arm as an example.
> For
> > > the
> > > > > > > simple model, I’ve no problem. However, for the two
> elements
> > > linear
> > > > > > > model (2Elin), I have difficulties to find a reasonable
> value
> > > > > > for ‘V0’
> > > > > > > parameter for the deltoid muscle. There is not a lot of
> > > litterature
> > > > > > > for this model. From what I know, the lateral part of the
> > > deltoid is
> > > > > > > responsible for the abduction and it is composed mostly
> of
> > > slow
> > > > > > twitch
> > > > > > > fibres. Can i put a high value of ‘V0’ because of that ?
> I
> > > mean, if
> > > > > > > this part of the muscle is composed of slow twitch
> fibres,
> > > does it
> > > > > > > make it not sensitive to contraction velocity ? I’m not
> very
> > > sure to
> > > > > > > understand well this parameter.
> > > > > > >
> > > > > > > Thank you for you help
> > > > > > >
> > > > > > > Pierre
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

Hi Pierre

The example on the user defined muscle is based on the interpolation
functions, but it could also have been equations like yours.

In principle you can write your own equations which are based on muscle
length and velocity.

So something in this direction might solve you problem

AnyMuscleModelUsr1 somemodel={

f0=819;

lmt=somemusclename.Lmt; //length on of the muscle depending on time â€¦

lo = 0.44???; // the initial length of the muscle
eps = (lmt - lo)/lo; // deformation of the muscle

S=fo*exp(-((eps+1).^(-0.4129)-1).^2/(0.105981));
};

I can not give you all the formulas of the three element model that would be
too muchâ€¦ it fact this muscle model contains a numeric solver that solved
the internal dof of the muscles. This internal dof is the tendon length. The
user defined model does not allow you to have a numeric solver but except
from this you can do almost as you likeâ€¦

We hope to add more info in the documentation on this topic at some point,
but right now it is not there, sorry.

Best regards

SÃ¸ren, AnyBody Support

From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of Pierre-Olivier Lemieux
Sent: 13 May 2008 03:30
To: anyscript@yahoogroups.com
Subject: [AnyScript] Re: Muscle models two elements linear

Hi guys,
I try to use a new muscle model. Here is the way that I write
it in Matlab :

f0 = 819;

lo = lm(1); % the initial length of the muscle

eps = (lm - lo)/lo; % deformation of the muscle

Sm = f0*exp(-((eps+1).^(-0.4129)-1).^2/(0.105981));

I want to know hot to write it in AnyBody. I checked the exemple
'UserDefinedMuscle.any ', but I think that it’s not exactly what I
need to know.

I have an other question. Can it be possible to know the exact
formulas of the 3 element type model that you propose? I’ve found what
I believe to be the V0 formula for this model and it gives me :

V0 = -Lfbar*(K1 + K2*Fcfast)

But I’m still not sure about the rest of the formulas.

Thank you for your support.

Pierre

— In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com,
“AnyBody Support” <support@…> wrote:
>
> Hi,
>
> Yes it sounds reasonable. I understand your 2D model is in the plane
> of the scapula. I think you can use the same value for the deltoid in
> the 2D model.
> It is a good idea to look at the tutorials, lot of things are well
> explained there.
>
> Best regards,
> Sylvain, AnyBody Support.
>
>
>
>
> — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com,
“Pierre-Olivier Lemieux”
> <pothekid@> wrote:
> >
> > Hi guys,
> > thank you for you help. I did the calibration for the two
> > muscle models (2E lin & 3E). However, I’ve seen that in the 3D model
> > of the upper arm, the calibration is done with a 10 degrees
> abduction
> > for the scapular deltoid. I consider that the mean deltoid is
> > representative of the abduction in the plane of the scapula. Thus,
> do
> > you think that I can use the same value for my 2D model
> calibration ?
> >
> > I’ve found added information about the muscle models on the new
> > updated tutorials. Before, I was working with the 2006 versions.
> >
> > Thank you again
> >
> > Pierre
> >
> >
> > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com,
“AnyBody Support” <support@>
> wrote:
> > >
> > > Hi Pierre Olivier,
> > >
> > > As you understood, the muscle’s neutral position is the position
> (for
> > > a certain movement) where the muscle has is optimal strength.
> That
> > > mean at this position the muscle is able to provide his maximum
> force
> > > F0. This position is typically the one where you need the more
> your
> > > muscle during the movement. For example if you lift some weight
> with
> > > your arm using your biceps, you will feel the position you are
> > > stronger is for an elbow flexion of approximately 90 degrees.
> This is
> > > where your biceps has his optimal strength. We use this
> assumption
> > > for the calibration. You may see the calibration sequence drive
> the
> > > body in different positions, they are chosen so that for each
> > > position a set of muscle is in the position where they are
> supposed
> > > to be the strongest.
> > >
> > > The aim of the calibration is to adjust the tendon length so that
> the
> > > muscle (the contractile element) has is optimal length
> (corresponding
> > > to his optimal strength) at the neutral position explained above.
> The
> > > two elements model also takes into account the tendon length and
> the
> > > contractile element length. So the problem is the same as for the
> > > three elements model: unless you already know the appropriate
> tendon
> > > length, you should run a calibration sequence. If you don’t run
> it
> > > you take the risk to get over stretched muscles without strength.
> > >
> > > Best regards,
> > > Sylvain, AnyBody Support.
> > >
> > >
> > >
> > >
> > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com, “Pierre-Olivier Lemieux”
> > > <pothekid@> wrote:
> > > >
> > > > Hi guys,
> > > > I’ve an other question regarding the muscle models. What
> is
> > > the
> > > > muscle’s neutral position ? I know that it is related to the
> > > > calibration and I know that at this position, the muscle has is
> > > > optimal strength, but does it means that’s because it does not
> > > develop
> > > > any force ? What about the calibration, do I need to do it for
> the
> > > > “two elements model” also ?
> > > >
> > > > Thank you for the support.
> > > >
> > > > Pierre
> > > >
> > > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com, “Pierre-Olivier Lemieux”
> > > > <pothekid@> wrote:
> > > > >
> > > > > Hi John,
> > > > > thank you for your advices. Yes, eventually I will
> come to
> > > the
> > > > > 3-elements model soon, but before I have to review the 2
> elements
> > > to
> > > > > prove that its not sufficient for what I need. Also, my
> > > supervisors
> > > > > asked me to explain them the way that these models works. At
> the
> > > same
> > > > > time, it allow me to know a little bit more about the
> software.
> > > > >
> > > > > I saw that in the tutorial, they put a minimal value of -0.3
> m/s
> > > for
> > > > > the V0 parameter, is it a good value to use for the deltoid
> > > muscle for
> > > > > instance ? In my model, the velocity is very reduced and I
> think
> > > that
> > > > > it would not have any effect on the strength of the muscle,
> but I
> > > > > still want to know what is the limit of contraction velocity
> for
> > > the
> > > > > muscle. If you don’t know, it’s ok, I will find a estimated
> value
> > > by
> > > > > doing some tests.
> > > > >
> > > > > For the slow and fast twitch, it seems to have some
> differences
> > > > > between the divisions of the deltoid muscle, from the new
> study of
> > > > > Gorelick and Brown (2007). However, the ‘Fcfast’ of all the
> > > divisions
> > > > > in AnyBody are set to 40%. Maybe it should have some
> improvement
> > > to
> > > > > the model by considering this article.
> > > > >
> > > > > Here is the complete reference, if you didn’t read it
> > > > >
> > > > > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic
> assessment of
> > > > > contractile properties within seven segments of the human
> deltoid
> > > > > muscle Â». European Journal of Applied Physiology, vol. 100,
> no 1,
> > > p.
> > > > > 35-44.
> > > > >
> > > > > Thank you for your support and have a great summer.
> > > > >
> > > > > Pierre
> > > > >
> > > > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com, “John Rasmussen” <jr@>
> wrote:
> > > > > >
> > > > > > Hi Pierre-Olivier,
> > > > > >
> > > > > > Fast twitch fibers are fast and slow twitch fibers are
> slow. So
> > > if
> > > > > > the lateral deltoid mostly has slow twitch fibers then it
> is
> > > likely
> > > > > > to be MORE sensible to velocity and you should consequently
> use
> > > a LOW
> > > > > > value of V0. Remember, V0 is the velocity at which the
> muscle
> > > > > > completely loses its strength.
> > > > > >
> > > > > > Have you considered using the three-element muscle mudel
> > > instead? It
> > > > > > allows you to input fiber length and the ratio of fast to
> slow
> > > twitch
> > > > > > fibers, and you do not have to worry about what V0 is. The
> > > muscle
> > > > > > model works that out automatically.
> > > > > >
> > > > > > Best regards,
> > > > > > John
> > > > > >
> > > > > >
> > > > > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com, “Pierre-Olivier Lemieux”
> > > > > > <pothekid@> wrote:
> > > > > > >
> > > > > > > Hi guys,
> > > > > > > I’m working on muscle models of Anybody and I try
> to
> > > explain
> > > > > > > how they work for an abduction of the arm as an example.
> For
> > > the
> > > > > > > simple model, I’ve no problem. However, for the two
> elements
> > > linear
> > > > > > > model (2Elin), I have difficulties to find a reasonable
> value
> > > > > > for ‘V0’
> > > > > > > parameter for the deltoid muscle. There is not a lot of
> > > litterature
> > > > > > > for this model. From what I know, the lateral part of the
> > > deltoid is
> > > > > > > responsible for the abduction and it is composed mostly
> of
> > > slow
> > > > > > twitch
> > > > > > > fibres. Can i put a high value of ‘V0’ because of that ?
> I
> > > mean, if
> > > > > > > this part of the muscle is composed of slow twitch
> fibres,
> > > does it
> > > > > > > make it not sensitive to contraction velocity ? I’m not
> very
> > > sure to
> > > > > > > understand well this parameter.
> > > > > > >
> > > > > > > Thank you for you help
> > > > > > >
> > > > > > > Pierre
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

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

Hi Soeren,
thank you for your help. I’m back in the 2e linear model.
Actually, I try to find the formula for the tendon length. As I see in
the tutorial, the force-deformation relationship is linear.

I give you an example of the steps that I follow to find the tendon
length (under "TendonLength.zip).

When I use this formula to compare it with the tendon length of
Anybody, the results are not the same. After some researches, I found
that ‘epsilonbar’ was replaced by ‘Lfbar’ in the formula, as you can
see at the bottom of the example.

Could it be a mistake of programming or maybe I’ve misunderstood
something ?

thank you for your help.

Pierre

— In anyscript@yahoogroups.com, “AnyBody Support” <support@…> wrote:
>
> Hi Pierre
>
>
>
> The example on the user defined muscle is based on the interpolation
> functions, but it could also have been equations like yours.
>
>
>
> In principle you can write your own equations which are based on muscle
> length and velocity.
>
>
>
> So something in this direction might solve you problem
>
>
>
> AnyMuscleModelUsr1 somemodel={
>
>
>
> f0=819;
>
> lmt=somemusclename.Lmt; //length on of the muscle depending on time â€¦
>
> lo = 0.44???; // the initial length of the muscle
> eps = (lmt - lo)/lo; // deformation of the muscle
>
> S=foexp(-((eps+1).^(-0.4129)-1).^2/(0.105981));
> };
>
>
>
> I can not give you all the formulas of the three element model that
would be
> too muchâ€¦ it fact this muscle model contains a numeric solver that
solved
> the internal dof of the muscles. This internal dof is the tendon
length. The
> user defined model does not allow you to have a numeric solver but
except
> from this you can do almost as you likeâ€¦
>
> We hope to add more info in the documentation on this topic at some
point,
> but right now it is not there, sorry.
>
>
>
> Best regards
>
> SÃ¸ren, AnyBody Support
>
>
>
> _____
>
> From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com]
On Behalf
> Of Pierre-Olivier Lemieux
> Sent: 13 May 2008 03:30
> To: anyscript@yahoogroups.com
> Subject: [AnyScript] Re: Muscle models two elements linear
>
>
>
> Hi guys,
> I try to use a new muscle model. Here is the way that I write
> it in Matlab :
>
> f0 = 819;
>
> lo = lm(1); % the initial length of the muscle
>
> eps = (lm - lo)/lo; % deformation of the muscle
>
> Sm = f0
exp(-((eps+1).^(-0.4129)-1).^2/(0.105981));
>
> I want to know hot to write it in AnyBody. I checked the exemple
> 'UserDefinedMuscle.any ', but I think that it’s not exactly what I
> need to know.
>
> I have an other question. Can it be possible to know the exact
> formulas of the 3 element type model that you propose? I’ve found what
> I believe to be the V0 formula for this model and it gives me :
>
> V0 = -Lfbar*(K1 + K2*Fcfast)
>
> But I’m still not sure about the rest of the formulas.
>
> Thank you for your support.
>
> Pierre
>
> — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com,
> “AnyBody Support” <support@> wrote:
> >
> > Hi,
> >
> > Yes it sounds reasonable. I understand your 2D model is in the plane
> > of the scapula. I think you can use the same value for the deltoid in
> > the 2D model.
> > It is a good idea to look at the tutorials, lot of things are well
> > explained there.
> >
> > Best regards,
> > Sylvain, AnyBody Support.
> >
> >
> >
> >
> > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com,
> “Pierre-Olivier Lemieux”
> > <pothekid@> wrote:
> > >
> > > Hi guys,
> > > thank you for you help. I did the calibration for the two
> > > muscle models (2E lin & 3E). However, I’ve seen that in the 3D model
> > > of the upper arm, the calibration is done with a 10 degrees
> > abduction
> > > for the scapular deltoid. I consider that the mean deltoid is
> > > representative of the abduction in the plane of the scapula. Thus,
> > do
> > > you think that I can use the same value for my 2D model
> > calibration ?
> > >
> > > I’ve found added information about the muscle models on the new
> > > updated tutorials. Before, I was working with the 2006 versions.
> > >
> > > Thank you again
> > >
> > > Pierre
> > >
> > >
> > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com,
> “AnyBody Support” <support@>
> > wrote:
> > > >
> > > > Hi Pierre Olivier,
> > > >
> > > > As you understood, the muscle’s neutral position is the position
> > (for
> > > > a certain movement) where the muscle has is optimal strength.
> > That
> > > > mean at this position the muscle is able to provide his maximum
> > force
> > > > F0. This position is typically the one where you need the more
> > your
> > > > muscle during the movement. For example if you lift some weight
> > with
> > > > your arm using your biceps, you will feel the position you are
> > > > stronger is for an elbow flexion of approximately 90 degrees.
> > This is
> > > > where your biceps has his optimal strength. We use this
> > assumption
> > > > for the calibration. You may see the calibration sequence drive
> > the
> > > > body in different positions, they are chosen so that for each
> > > > position a set of muscle is in the position where they are
> > supposed
> > > > to be the strongest.
> > > >
> > > > The aim of the calibration is to adjust the tendon length so that
> > the
> > > > muscle (the contractile element) has is optimal length
> > (corresponding
> > > > to his optimal strength) at the neutral position explained above.
> > The
> > > > two elements model also takes into account the tendon length and
> > the
> > > > contractile element length. So the problem is the same as for the
> > > > three elements model: unless you already know the appropriate
> > tendon
> > > > length, you should run a calibration sequence. If you don’t run
> > it
> > > > you take the risk to get over stretched muscles without strength.
> > > >
> > > > Best regards,
> > > > Sylvain, AnyBody Support.
> > > >
> > > >
> > > >
> > > >
> > > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
> ps.com, “Pierre-Olivier Lemieux”
> > > > <pothekid@> wrote:
> > > > >
> > > > > Hi guys,
> > > > > I’ve an other question regarding the muscle models. What
> > is
> > > > the
> > > > > muscle’s neutral position ? I know that it is related to the
> > > > > calibration and I know that at this position, the muscle has is
> > > > > optimal strength, but does it means that’s because it does not
> > > > develop
> > > > > any force ? What about the calibration, do I need to do it for
> > the
> > > > > “two elements model” also ?
> > > > >
> > > > > Thank you for the support.
> > > > >
> > > > > Pierre
> > > > >
> > > > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
> ps.com, “Pierre-Olivier Lemieux”
> > > > > <pothekid@> wrote:
> > > > > >
> > > > > > Hi John,
> > > > > > thank you for your advices. Yes, eventually I will
> > come to
> > > > the
> > > > > > 3-elements model soon, but before I have to review the 2
> > elements
> > > > to
> > > > > > prove that its not sufficient for what I need. Also, my
> > > > supervisors
> > > > > > asked me to explain them the way that these models works. At
> > the
> > > > same
> > > > > > time, it allow me to know a little bit more about the
> > software.
> > > > > >
> > > > > > I saw that in the tutorial, they put a minimal value of -0.3
> > m/s
> > > > for
> > > > > > the V0 parameter, is it a good value to use for the deltoid
> > > > muscle for
> > > > > > instance ? In my model, the velocity is very reduced and I
> > think
> > > > that
> > > > > > it would not have any effect on the strength of the muscle,
> > but I
> > > > > > still want to know what is the limit of contraction velocity
> > for
> > > > the
> > > > > > muscle. If you don’t know, it’s ok, I will find a estimated
> > value
> > > > by
> > > > > > doing some tests.
> > > > > >
> > > > > > For the slow and fast twitch, it seems to have some
> > differences
> > > > > > between the divisions of the deltoid muscle, from the new
> > study of
> > > > > > Gorelick and Brown (2007). However, the ‘Fcfast’ of all the
> > > > divisions
> > > > > > in AnyBody are set to 40%. Maybe it should have some
> > improvement
> > > > to
> > > > > > the model by considering this article.
> > > > > >
> > > > > > Here is the complete reference, if you didn’t read it
> > already :
> > > > > >
> > > > > > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic
> > assessment of
> > > > > > contractile properties within seven segments of the human
> > deltoid
> > > > > > muscle Â». European Journal of Applied Physiology, vol. 100,
> > no 1,
> > > > p.
> > > > > > 35-44.
> > > > > >
> > > > > > Thank you for your support and have a great summer.
> > > > > >
> > > > > > Pierre
> > > > > >
> > > > > > — In anyscript@yahoogrou
<mailto:anyscript%40yahoogroups.com>
> ps.com, “John Rasmussen” <jr@>
> > wrote:
> > > > > > >
> > > > > > > Hi Pierre-Olivier,
> > > > > > >
> > > > > > > Fast twitch fibers are fast and slow twitch fibers are
> > slow. So
> > > > if
> > > > > > > the lateral deltoid mostly has slow twitch fibers then it
> > is
> > > > likely
> > > > > > > to be MORE sensible to velocity and you should consequently
> > use
> > > > a LOW
> > > > > > > value of V0. Remember, V0 is the velocity at which the
> > muscle
> > > > > > > completely loses its strength.
> > > > > > >
> > > > > > > Have you considered using the three-element muscle mudel
> > > > instead? It
> > > > > > > allows you to input fiber length and the ratio of fast to
> > slow
> > > > twitch
> > > > > > > fibers, and you do not have to worry about what V0 is. The
> > > > muscle
> > > > > > > model works that out automatically.
> > > > > > >
> > > > > > > Best regards,
> > > > > > > John
> > > > > > >
> > > > > > >
> > > > > > > — In anyscript@yahoogrou
<mailto:anyscript%40yahoogroups.com>
> ps.com, “Pierre-Olivier Lemieux”
> > > > > > > <pothekid@> wrote:
> > > > > > > >
> > > > > > > > Hi guys,
> > > > > > > > I’m working on muscle models of Anybody and I try
> > to
> > > > explain
> > > > > > > > how they work for an abduction of the arm as an example.
> > For
> > > > the
> > > > > > > > simple model, I’ve no problem. However, for the two
> > elements
> > > > linear
> > > > > > > > model (2Elin), I have difficulties to find a reasonable
> > value
> > > > > > > for ‘V0’
> > > > > > > > parameter for the deltoid muscle. There is not a lot of
> > > > litterature
> > > > > > > > for this model. From what I know, the lateral part of the
> > > > deltoid is
> > > > > > > > responsible for the abduction and it is composed mostly
> > of
> > > > slow
> > > > > > > twitch
> > > > > > > > fibres. Can i put a high value of ‘V0’ because of that ?
> > I
> > > > mean, if
> > > > > > > > this part of the muscle is composed of slow twitch
> > fibres,
> > > > does it
> > > > > > > > make it not sensitive to contraction velocity ? I’m not
> > very
> > > > sure to
> > > > > > > > understand well this parameter.
> > > > > > > >
> > > > > > > > Thank you for you help
> > > > > > > >
> > > > > > > > Pierre
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

Hi again,
the file needs Mathtype to be readable. So I put a .pdf format
under “TendonLength2.zip”.

Thank you

Pierre.

— In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
<pothekid@…> wrote:
>
> Hi Soeren,
> thank you for your help. I’m back in the 2e linear model.
> Actually, I try to find the formula for the tendon length. As I see in
> the tutorial, the force-deformation relationship is linear.
>
> I give you an example of the steps that I follow to find the tendon
> length (under "TendonLength.zip).
>
> When I use this formula to compare it with the tendon length of
> Anybody, the results are not the same. After some researches, I found
> that ‘epsilonbar’ was replaced by ‘Lfbar’ in the formula, as you can
> see at the bottom of the example.
>
> Could it be a mistake of programming or maybe I’ve misunderstood
> something ?
>
> thank you for your help.
>
> Pierre
>
>
> — In anyscript@yahoogroups.com, “AnyBody Support” <support@> wrote:
> >
> > Hi Pierre
> >
> >
> >
> > The example on the user defined muscle is based on the interpolation
> > functions, but it could also have been equations like yours.
> >
> >
> >
> > In principle you can write your own equations which are based on
muscle
> > length and velocity.
> >
> >
> >
> > So something in this direction might solve you problem
> >
> >
> >
> > AnyMuscleModelUsr1 somemodel={
> >
> >
> >
> > f0=819;
> >
> > lmt=somemusclename.Lmt; //length on of the muscle depending on time â€¦
> >
> > lo = 0.44???; // the initial length of the muscle
> > eps = (lmt - lo)/lo; // deformation of the muscle
> >
> > S=foexp(-((eps+1).^(-0.4129)-1).^2/(0.105981));
> > };
> >
> >
> >
> > I can not give you all the formulas of the three element model that
> would be
> > too muchâ€¦ it fact this muscle model contains a numeric solver that
> solved
> > the internal dof of the muscles. This internal dof is the tendon
> length. The
> > user defined model does not allow you to have a numeric solver but
> except
> > from this you can do almost as you likeâ€¦
> >
> > We hope to add more info in the documentation on this topic at some
> point,
> > but right now it is not there, sorry.
> >
> >
> >
> > Best regards
> >
> > SÃ¸ren, AnyBody Support
> >
> >
> >
> > _____
> >
> > From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com]
> On Behalf
> > Of Pierre-Olivier Lemieux
> > Sent: 13 May 2008 03:30
> > To: anyscript@yahoogroups.com
> > Subject: [AnyScript] Re: Muscle models two elements linear
> >
> >
> >
> > Hi guys,
> > I try to use a new muscle model. Here is the way that I write
> > it in Matlab :
> >
> > f0 = 819;
> >
> > lo = lm(1); % the initial length of the muscle
> >
> > eps = (lm - lo)/lo; % deformation of the muscle
> >
> > Sm = f0
exp(-((eps+1).^(-0.4129)-1).^2/(0.105981));
> >
> > I want to know hot to write it in AnyBody. I checked the exemple
> > 'UserDefinedMuscle.any ', but I think that it’s not exactly what I
> > need to know.
> >
> > I have an other question. Can it be possible to know the exact
> > formulas of the 3 element type model that you propose? I’ve found what
> > I believe to be the V0 formula for this model and it gives me :
> >
> > V0 = -Lfbar*(K1 + K2*Fcfast)
> >
> > But I’m still not sure about the rest of the formulas.
> >
> > Thank you for your support.
> >
> > Pierre
> >
> > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com,
> > “AnyBody Support” <support@> wrote:
> > >
> > > Hi,
> > >
> > > Yes it sounds reasonable. I understand your 2D model is in the
plane
> > > of the scapula. I think you can use the same value for the
deltoid in
> > > the 2D model.
> > > It is a good idea to look at the tutorials, lot of things are well
> > > explained there.
> > >
> > > Best regards,
> > > Sylvain, AnyBody Support.
> > >
> > >
> > >
> > >
> > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
> ps.com,
> > “Pierre-Olivier Lemieux”
> > > <pothekid@> wrote:
> > > >
> > > > Hi guys,
> > > > thank you for you help. I did the calibration for the two
> > > > muscle models (2E lin & 3E). However, I’ve seen that in the 3D
model
> > > > of the upper arm, the calibration is done with a 10 degrees
> > > abduction
> > > > for the scapular deltoid. I consider that the mean deltoid is
> > > > representative of the abduction in the plane of the scapula.
Thus,
> > > do
> > > > you think that I can use the same value for my 2D model
> > > calibration ?
> > > >
> > > > I’ve found added information about the muscle models on the new
> > > > updated tutorials. Before, I was working with the 2006 versions.
> > > >
> > > > Thank you again
> > > >
> > > > Pierre
> > > >
> > > >
> > > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
> ps.com,
> > “AnyBody Support” <support@>
> > > wrote:
> > > > >
> > > > > Hi Pierre Olivier,
> > > > >
> > > > > As you understood, the muscle’s neutral position is the
position
> > > (for
> > > > > a certain movement) where the muscle has is optimal strength.
> > > That
> > > > > mean at this position the muscle is able to provide his maximum
> > > force
> > > > > F0. This position is typically the one where you need the more
> > > your
> > > > > muscle during the movement. For example if you lift some weight
> > > with
> > > > > your arm using your biceps, you will feel the position you are
> > > > > stronger is for an elbow flexion of approximately 90 degrees.
> > > This is
> > > > > where your biceps has his optimal strength. We use this
> > > assumption
> > > > > for the calibration. You may see the calibration sequence drive
> > > the
> > > > > body in different positions, they are chosen so that for each
> > > > > position a set of muscle is in the position where they are
> > > supposed
> > > > > to be the strongest.
> > > > >
> > > > > The aim of the calibration is to adjust the tendon length so
that
> > > the
> > > > > muscle (the contractile element) has is optimal length
> > > (corresponding
> > > > > to his optimal strength) at the neutral position explained
above.
> > > The
> > > > > two elements model also takes into account the tendon length
and
> > > the
> > > > > contractile element length. So the problem is the same as
for the
> > > > > three elements model: unless you already know the appropriate
> > > tendon
> > > > > length, you should run a calibration sequence. If you don’t run
> > > it
> > > > > you take the risk to get over stretched muscles without
strength.
> > > > >
> > > > > Best regards,
> > > > > Sylvain, AnyBody Support.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
> > ps.com, “Pierre-Olivier Lemieux”
> > > > > <pothekid@> wrote:
> > > > > >
> > > > > > Hi guys,
> > > > > > I’ve an other question regarding the muscle models. What
> > > is
> > > > > the
> > > > > > muscle’s neutral position ? I know that it is related to the
> > > > > > calibration and I know that at this position, the muscle
has is
> > > > > > optimal strength, but does it means that’s because it does
not
> > > > > develop
> > > > > > any force ? What about the calibration, do I need to do it
for
> > > the
> > > > > > “two elements model” also ?
> > > > > >
> > > > > > Thank you for the support.
> > > > > >
> > > > > > Pierre
> > > > > >
> > > > > > — In anyscript@yahoogrou
<mailto:anyscript%40yahoogroups.com>
> > ps.com, “Pierre-Olivier Lemieux”
> > > > > > <pothekid@> wrote:
> > > > > > >
> > > > > > > Hi John,
> > > > > > > thank you for your advices. Yes, eventually I will
> > > come to
> > > > > the
> > > > > > > 3-elements model soon, but before I have to review the 2
> > > elements
> > > > > to
> > > > > > > prove that its not sufficient for what I need. Also, my
> > > > > supervisors
> > > > > > > asked me to explain them the way that these models
works. At
> > > the
> > > > > same
> > > > > > > time, it allow me to know a little bit more about the
> > > software.
> > > > > > >
> > > > > > > I saw that in the tutorial, they put a minimal value of
-0.3
> > > m/s
> > > > > for
> > > > > > > the V0 parameter, is it a good value to use for the deltoid
> > > > > muscle for
> > > > > > > instance ? In my model, the velocity is very reduced and I
> > > think
> > > > > that
> > > > > > > it would not have any effect on the strength of the muscle,
> > > but I
> > > > > > > still want to know what is the limit of contraction
velocity
> > > for
> > > > > the
> > > > > > > muscle. If you don’t know, it’s ok, I will find a estimated
> > > value
> > > > > by
> > > > > > > doing some tests.
> > > > > > >
> > > > > > > For the slow and fast twitch, it seems to have some
> > > differences
> > > > > > > between the divisions of the deltoid muscle, from the new
> > > study of
> > > > > > > Gorelick and Brown (2007). However, the ‘Fcfast’ of all the
> > > > > divisions
> > > > > > > in AnyBody are set to 40%. Maybe it should have some
> > > improvement
> > > > > to
> > > > > > > the model by considering this article.
> > > > > > >
> > > > > > > Here is the complete reference, if you didn’t read it
> > > already :
> > > > > > >
> > > > > > > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic
> > > assessment of
> > > > > > > contractile properties within seven segments of the human
> > > deltoid
> > > > > > > muscle Â». European Journal of Applied Physiology, vol. 100,
> > > no 1,
> > > > > p.
> > > > > > > 35-44.
> > > > > > >
> > > > > > > Thank you for your support and have a great summer.
> > > > > > >
> > > > > > > Pierre
> > > > > > >
> > > > > > > — In anyscript@yahoogrou
> <mailto:anyscript%40yahoogroups.com>
> > ps.com, “John Rasmussen” <jr@>
> > > wrote:
> > > > > > > >
> > > > > > > > Hi Pierre-Olivier,
> > > > > > > >
> > > > > > > > Fast twitch fibers are fast and slow twitch fibers are
> > > slow. So
> > > > > if
> > > > > > > > the lateral deltoid mostly has slow twitch fibers then it
> > > is
> > > > > likely
> > > > > > > > to be MORE sensible to velocity and you should
consequently
> > > use
> > > > > a LOW
> > > > > > > > value of V0. Remember, V0 is the velocity at which the
> > > muscle
> > > > > > > > completely loses its strength.
> > > > > > > >
> > > > > > > > Have you considered using the three-element muscle mudel
> > > > > instead? It
> > > > > > > > allows you to input fiber length and the ratio of fast to
> > > slow
> > > > > twitch
> > > > > > > > fibers, and you do not have to worry about what V0 is.
The
> > > > > muscle
> > > > > > > > model works that out automatically.
> > > > > > > >
> > > > > > > > Best regards,
> > > > > > > > John
> > > > > > > >
> > > > > > > >
> > > > > > > > — In anyscript@yahoogrou
> <mailto:anyscript%40yahoogroups.com>
> > ps.com, “Pierre-Olivier Lemieux”
> > > > > > > > <pothekid@> wrote:
> > > > > > > > >
> > > > > > > > > Hi guys,
> > > > > > > > > I’m working on muscle models of Anybody and I try
> > > to
> > > > > explain
> > > > > > > > > how they work for an abduction of the arm as an
example.
> > > For
> > > > > the
> > > > > > > > > simple model, I’ve no problem. However, for the two
> > > elements
> > > > > linear
> > > > > > > > > model (2Elin), I have difficulties to find a reasonable
> > > value
> > > > > > > > for ‘V0’
> > > > > > > > > parameter for the deltoid muscle. There is not a lot of
> > > > > litterature
> > > > > > > > > for this model. From what I know, the lateral part
of the
> > > > > deltoid is
> > > > > > > > > responsible for the abduction and it is composed mostly
> > > of
> > > > > slow
> > > > > > > > twitch
> > > > > > > > > fibres. Can i put a high value of ‘V0’ because of
that ?
> > > I
> > > > > mean, if
> > > > > > > > > this part of the muscle is composed of slow twitch
> > > fibres,
> > > > > does it
> > > > > > > > > make it not sensitive to contraction velocity ? I’m not
> > > very
> > > > > sure to
> > > > > > > > > understand well this parameter.
> > > > > > > > >
> > > > > > > > > Thank you for you help
> > > > > > > > >
> > > > > > > > > Pierre
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>

Hi Pierre,

I have looked for that difference you found and the formula and you
are actually right, there was a mistake in our formula. We apologize
for this, it has been corrected now.
Thank you very much for made us aware of it.
The good news is that it does not affect the result of the force and
activity, those ones are depending on Lt0 but not on Lt. Lt is an
independent output value. So all the others outputs (force, activity,
etcâ€¦) are still valid.

Thank you again.

Best regards,
Sylvain, AnyBody Support.

— In anyscript@yahoogroups.com, “Pierre-Olivier Lemieux”
<pothekid@…> wrote:
>
> Hi Soeren,
> thank you for your help. I’m back in the 2e linear model.
> Actually, I try to find the formula for the tendon length. As I see
in
> the tutorial, the force-deformation relationship is linear.
>
> I give you an example of the steps that I follow to find the tendon
> length (under "TendonLength.zip).
>
> When I use this formula to compare it with the tendon length of
> Anybody, the results are not the same. After some researches, I
found
> that ‘epsilonbar’ was replaced by ‘Lfbar’ in the formula, as you can
> see at the bottom of the example.
>
> Could it be a mistake of programming or maybe I’ve misunderstood
> something ?
>
> thank you for your help.
>
> Pierre
>
>
> — In anyscript@yahoogroups.com, “AnyBody Support” <support@>
wrote:
> >
> > Hi Pierre
> >
> >
> >
> > The example on the user defined muscle is based on the
interpolation
> > functions, but it could also have been equations like yours.
> >
> >
> >
> > In principle you can write your own equations which are based on
muscle
> > length and velocity.
> >
> >
> >
> > So something in this direction might solve you problem
> >
> >
> >
> > AnyMuscleModelUsr1 somemodel={
> >
> >
> >
> > f0=819;
> >
> > lmt=somemusclename.Lmt; //length on of the muscle depending on
time â€¦
> >
> > lo = 0.44???; // the initial length of the muscle
> > eps = (lmt - lo)/lo; // deformation of the muscle
> >
> > S=foexp(-((eps+1).^(-0.4129)-1).^2/(0.105981));
> > };
> >
> >
> >
> > I can not give you all the formulas of the three element model
that
> would be
> > too muchâ€¦ it fact this muscle model contains a numeric solver that
> solved
> > the internal dof of the muscles. This internal dof is the tendon
> length. The
> > user defined model does not allow you to have a numeric solver but
> except
> > from this you can do almost as you likeâ€¦
> >
> > We hope to add more info in the documentation on this topic at
some
> point,
> > but right now it is not there, sorry.
> >
> >
> >
> > Best regards
> >
> > SÃ¸ren, AnyBody Support
> >
> >
> >
> > _____
> >
> > From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com]
> On Behalf
> > Of Pierre-Olivier Lemieux
> > Sent: 13 May 2008 03:30
> > To: anyscript@yahoogroups.com
> > Subject: [AnyScript] Re: Muscle models two elements linear
> >
> >
> >
> > Hi guys,
> > I try to use a new muscle model. Here is the way that I write
> > it in Matlab :
> >
> > f0 = 819;
> >
> > lo = lm(1); % the initial length of the muscle
> >
> > eps = (lm - lo)/lo; % deformation of the muscle
> >
> > Sm = f0
exp(-((eps+1).^(-0.4129)-1).^2/(0.105981));
> >
> > I want to know hot to write it in AnyBody. I checked the exemple
> > 'UserDefinedMuscle.any ', but I think that it’s not exactly what I
> > need to know.
> >
> > I have an other question. Can it be possible to know the exact
> > formulas of the 3 element type model that you propose? I’ve found
what
> > I believe to be the V0 formula for this model and it gives me :
> >
> > V0 = -Lfbar*(K1 + K2*Fcfast)
> >
> > But I’m still not sure about the rest of the formulas.
> >
> > Thank you for your support.
> >
> > Pierre
> >
> > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
ps.com,
> > “AnyBody Support” <support@> wrote:
> > >
> > > Hi,
> > >
> > > Yes it sounds reasonable. I understand your 2D model is in the
plane
> > > of the scapula. I think you can use the same value for the
deltoid in
> > > the 2D model.
> > > It is a good idea to look at the tutorials, lot of things are
well
> > > explained there.
> > >
> > > Best regards,
> > > Sylvain, AnyBody Support.
> > >
> > >
> > >
> > >
> > > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com>
> ps.com,
> > “Pierre-Olivier Lemieux”
> > > <pothekid@> wrote:
> > > >
> > > > Hi guys,
> > > > thank you for you help. I did the calibration for the two
> > > > muscle models (2E lin & 3E). However, I’ve seen that in the
3D model
> > > > of the upper arm, the calibration is done with a 10 degrees
> > > abduction
> > > > for the scapular deltoid. I consider that the mean deltoid is
> > > > representative of the abduction in the plane of the scapula.
Thus,
> > > do
> > > > you think that I can use the same value for my 2D model
> > > calibration ?
> > > >
> > > > I’ve found added information about the muscle models on the
new
> > > > updated tutorials. Before, I was working with the 2006
versions.
> > > >
> > > > Thank you again
> > > >
> > > > Pierre
> > > >
> > > >
> > > > — In anyscript@yahoogrou <mailto:anyscript%
40yahoogroups.com>
> ps.com,
> > “AnyBody Support” <support@>
> > > wrote:
> > > > >
> > > > > Hi Pierre Olivier,
> > > > >
> > > > > As you understood, the muscle’s neutral position is the
position
> > > (for
> > > > > a certain movement) where the muscle has is optimal
strength.
> > > That
> > > > > mean at this position the muscle is able to provide his
maximum
> > > force
> > > > > F0. This position is typically the one where you need the
more
> > > your
> > > > > muscle during the movement. For example if you lift some
weight
> > > with
> > > > > your arm using your biceps, you will feel the position you
are
> > > > > stronger is for an elbow flexion of approximately 90
degrees.
> > > This is
> > > > > where your biceps has his optimal strength. We use this
> > > assumption
> > > > > for the calibration. You may see the calibration sequence
drive
> > > the
> > > > > body in different positions, they are chosen so that for
each
> > > > > position a set of muscle is in the position where they are
> > > supposed
> > > > > to be the strongest.
> > > > >
> > > > > The aim of the calibration is to adjust the tendon length
so that
> > > the
> > > > > muscle (the contractile element) has is optimal length
> > > (corresponding
> > > > > to his optimal strength) at the neutral position explained
above.
> > > The
> > > > > two elements model also takes into account the tendon
length and
> > > the
> > > > > contractile element length. So the problem is the same as
for the
> > > > > three elements model: unless you already know the
appropriate
> > > tendon
> > > > > length, you should run a calibration sequence. If you don’t
run
> > > it
> > > > > you take the risk to get over stretched muscles without
strength.
> > > > >
> > > > > Best regards,
> > > > > Sylvain, AnyBody Support.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > — In anyscript@yahoogrou <mailto:anyscript%
40yahoogroups.com>
> > ps.com, “Pierre-Olivier Lemieux”
> > > > > <pothekid@> wrote:
> > > > > >
> > > > > > Hi guys,
> > > > > > I’ve an other question regarding the muscle models. What
> > > is
> > > > > the
> > > > > > muscle’s neutral position ? I know that it is related to
the
> > > > > > calibration and I know that at this position, the muscle
has is
> > > > > > optimal strength, but does it means that’s because it
does not
> > > > > develop
> > > > > > any force ? What about the calibration, do I need to do
it for
> > > the
> > > > > > “two elements model” also ?
> > > > > >
> > > > > > Thank you for the support.
> > > > > >
> > > > > > Pierre
> > > > > >
> > > > > > — In anyscript@yahoogrou <mailto:anyscript%
40yahoogroups.com>
> > ps.com, “Pierre-Olivier Lemieux”
> > > > > > <pothekid@> wrote:
> > > > > > >
> > > > > > > Hi John,
> > > > > > > thank you for your advices. Yes, eventually I will
> > > come to
> > > > > the
> > > > > > > 3-elements model soon, but before I have to review the
2
> > > elements
> > > > > to
> > > > > > > prove that its not sufficient for what I need. Also, my
> > > > > supervisors
> > > > > > > asked me to explain them the way that these models
works. At
> > > the
> > > > > same
> > > > > > > time, it allow me to know a little bit more about the
> > > software.
> > > > > > >
> > > > > > > I saw that in the tutorial, they put a minimal value
of -0.3
> > > m/s
> > > > > for
> > > > > > > the V0 parameter, is it a good value to use for the
deltoid
> > > > > muscle for
> > > > > > > instance ? In my model, the velocity is very reduced
and I
> > > think
> > > > > that
> > > > > > > it would not have any effect on the strength of the
muscle,
> > > but I
> > > > > > > still want to know what is the limit of contraction
velocity
> > > for
> > > > > the
> > > > > > > muscle. If you don’t know, it’s ok, I will find a
estimated
> > > value
> > > > > by
> > > > > > > doing some tests.
> > > > > > >
> > > > > > > For the slow and fast twitch, it seems to have some
> > > differences
> > > > > > > between the divisions of the deltoid muscle, from the
new
> > > study of
> > > > > > > Gorelick and Brown (2007). However, the ‘Fcfast’ of all
the
> > > > > divisions
> > > > > > > in AnyBody are set to 40%. Maybe it should have some
> > > improvement
> > > > > to
> > > > > > > the model by considering this article.
> > > > > > >
> > > > > > > Here is the complete reference, if you didn’t read it
> > > already :
> > > > > > >
> > > > > > > Gorelick, M., et J. Brown. 2007. Â« Mechanomyographic
> > > assessment of
> > > > > > > contractile properties within seven segments of the
human
> > > deltoid
> > > > > > > muscle Â». European Journal of Applied Physiology, vol.
100,
> > > no 1,
> > > > > p.
> > > > > > > 35-44.
> > > > > > >
> > > > > > > Thank you for your support and have a great summer.
> > > > > > >
> > > > > > > Pierre
> > > > > > >
> > > > > > > — In anyscript@yahoogrou
> <mailto:anyscript%40yahoogroups.com>
> > ps.com, “John Rasmussen” <jr@>
> > > wrote:
> > > > > > > >
> > > > > > > > Hi Pierre-Olivier,
> > > > > > > >
> > > > > > > > Fast twitch fibers are fast and slow twitch fibers
are
> > > slow. So
> > > > > if
> > > > > > > > the lateral deltoid mostly has slow twitch fibers
then it
> > > is
> > > > > likely
> > > > > > > > to be MORE sensible to velocity and you should
consequently
> > > use
> > > > > a LOW
> > > > > > > > value of V0. Remember, V0 is the velocity at which
the
> > > muscle
> > > > > > > > completely loses its strength.
> > > > > > > >
> > > > > > > > Have you considered using the three-element muscle
mudel
> > > > > instead? It
> > > > > > > > allows you to input fiber length and the ratio of
fast to
> > > slow
> > > > > twitch
> > > > > > > > fibers, and you do not have to worry about what V0
is. The
> > > > > muscle
> > > > > > > > model works that out automatically.
> > > > > > > >
> > > > > > > > Best regards,
> > > > > > > > John
> > > > > > > >
> > > > > > > >
> > > > > > > > — In anyscript@yahoogrou
> <mailto:anyscript%40yahoogroups.com>
> > ps.com, “Pierre-Olivier Lemieux”
> > > > > > > > <pothekid@> wrote:
> > > > > > > > >
> > > > > > > > > Hi guys,
> > > > > > > > > I’m working on muscle models of Anybody and I try
> > > to
> > > > > explain
> > > > > > > > > how they work for an abduction of the arm as an
example.
> > > For
> > > > > the
> > > > > > > > > simple model, I’ve no problem. However, for the two
> > > elements
> > > > > linear
> > > > > > > > > model (2Elin), I have difficulties to find a
reasonable
> > > value
> > > > > > > > for ‘V0’
> > > > > > > > > parameter for the deltoid muscle. There is not a
lot of
> > > > > litterature
> > > > > > > > > for this model. From what I know, the lateral part
of the
> > > > > deltoid is
> > > > > > > > > responsible for the abduction and it is composed
mostly
> > > of
> > > > > slow
> > > > > > > > twitch
> > > > > > > > > fibres. Can i put a high value of ‘V0’ because of
that ?
> > > I
> > > > > mean, if
> > > > > > > > > this part of the muscle is composed of slow twitch
> > > fibres,
> > > > > does it
> > > > > > > > > make it not sensitive to contraction velocity ? I’m
not
> > > very
> > > > > sure to
> > > > > > > > > understand well this parameter.
> > > > > > > > >
> > > > > > > > > Thank you for you help
> > > > > > > > >
> > > > > > > > > Pierre
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>