# Knee model

Dear Soren,

I have looked through the bike model and i have come up with the main criteria i
needed to know and i am now concentrating on the Knee model i want to know some
information about the model and the forces acting on the knee?
Please if you can provide me with any information concerning the knee i will
appreciate it.

Thank you In Advance and with my Best Regards

## Nesreen Aboulkhair PhD Research Student. Office 309b Howell Building School of Engineering and Design Brunel Univesristy Uxbridge Middlesex UB8 3PH UK Tel: +44 1895 267 200 Email: Nesreen.Aboulkhair@brunel.ac.uk <mailto:Nesreen.Aboulkhair@brunel.ac.uk?> ?

From: anyscript@yahoogroups.com on behalf of AnyBody Support
Sent: Mon 10/30/2006 12:52 PM
To: anyscript@yahoogroups.com
Subject: [anyscript] Re: Bike Model 3D

Hi Nina

If you look in the Tutorial “Getting started with AnyScript”
(Not “Getting started”) Lesson 2 there is a description on how the
masses and inertia is defined. You can also look at the
tutorial “The Mechanical Elements” Lesson 1.

There is also a tutorial which is based on a 2d bike model, so you
might be able to find some of the abbrevations there this is in
the “Parameter studies and Optimization” Lesson 1.

RPM means rounds per min.

Best regards
SÃ¸ren, AnyBody Support

## — In anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com> , “Nesreen Aboulkhair” <nesreen.aboulkhair@…> wrote: > > Thank you for replying. but i found some of the terms in the script are not clear such as RPM? in the bike model so can you guide a bit further please on where i should find the abbreviations meanings. I have looked through the “Getting started” but i could not find any thing to answer my question about the mass inertia. > > Thank you In Advance and appreciating your cooperation. > > Nina > ----------------------------------------------------------

>
>
> ________________________________
>
> From: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com> on
behalf of AnyBody Support
> Sent: Mon 10/30/2006 11:46 AM
> To: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
> Subject: [anyscript] Re: Bike Model 3D
>
>
>
> Hi Nina
>
> I think it will be a good idea to run some of the tutorials, you
can
> find them in the menu of AnyBody under “Help ->Contents”.
> The “Getting started with AnyScript” will answer some of your
> questions about mass, inertia etc.
>
> The driving torque is defined in the
file “BikeFramesAndWheel.any”,
> the object named “CrankMoment” defines the variation of the
> crankmoment as a function of the pedalangle.
>
>
> Best regards
> SÃ¸ren, AnyBody Support
>
> — In anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
<mailto:anyscript%
40yahoogroups.com> , “nina_rama2002”
> <nesreen.aboulkhair@> wrote:
> >
> > Hi every one in anybody group,
> >
> > I’m new to this group and i am facing some confusion in
> understanding
> > the Bike Mode. Actually i have successfully run it but i needed
to
> > understand more about the parameters used in this model the Mass
> > Inertia of the bone, Muscles, Length of it and the calculation
of
> > joint forces and the joint tork against the trank???
> > Driving tork.
> > Thanks
> > Nina
> >
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

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

Hi Nesreen

If you use the Leg3d model you can find the knee in the file
Brep/aalborg/Leg3d/Jnt.any

The knee is made as a revolute joint, you can find it in the model
tree in HumanModel.Right.Leg.Jnt.Knee

In this joint you can find its reaction by clicking on the
Constraints.Reaction. Since it is a revolute joint there are 5
reactions three forces and two moments, they are given in the
coordinate system of the first node of the joint.

Best regards
SÃ¸ren AnyBody Support

## — In anyscript@yahoogroups.com, “Nesreen Aboulkhair” <nesreen.aboulkhair@…> wrote: > > Dear Soren, > > I have looked through the bike model and i have come up with the main criteria i needed to know and i am now concentrating on the Knee model i want to know some information about the model and the forces acting on the knee? > Please if you can provide me with any information concerning the knee i will appreciate it. > > Thank you In Advance and with my Best Regards > > > -------------------------------------------------------------------

> Nesreen Aboulkhair
> PhD Research Student.
> Office 309b
> Howell Building
> School of Engineering and Design
> Brunel Univesristy
> Uxbridge
> Middlesex
> UB8 3PH
> UK
> Tel: +44 1895 267 200
> Email: Nesreen.Aboulkhair@… <mailto:Nesreen.Aboulkhair@…?> ?
> --------------------------------------------------------
>
> ________________________________
>
> From: anyscript@yahoogroups.com on behalf of AnyBody Support
> Sent: Mon 10/30/2006 12:52 PM
> To: anyscript@yahoogroups.com
> Subject: [anyscript] Re: Bike Model 3D
>
>
>
> Hi Nina
>
> If you look in the Tutorial “Getting started with AnyScript”
> (Not “Getting started”) Lesson 2 there is a description on how the
> masses and inertia is defined. You can also look at the
> tutorial “The Mechanical Elements” Lesson 1.
>
> There is also a tutorial which is based on a 2d bike model, so you
> might be able to find some of the abbrevations there this is in
> the “Parameter studies and Optimization” Lesson 1.
>
> RPM means rounds per min.
>
>
> Best regards
> SÃ¸ren, AnyBody Support
>
> — In anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> , “Nesreen Aboulkhair”
> <nesreen.aboulkhair@> wrote:
> >
> > Thank you for replying. but i found some of the terms in the
> script are not clear such as RPM? in the bike model so can you
guide
> a bit further please on where i should find the abbreviations
> meanings. I have looked through the “Getting started” but i could
> not find any thing to answer my question about the mass inertia.
> >
> >
> > Nina
> > ----------------------------------------------------------
> -
> >
> >
> > ________________________________
> >
> > From: anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> on behalf of AnyBody Support
> > Sent: Mon 10/30/2006 11:46 AM
> > To: anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com>
> > Subject: [anyscript] Re: Bike Model 3D
> >
> >
> >
> > Hi Nina
> >
> > I think it will be a good idea to run some of the tutorials, you
> can
> > find them in the menu of AnyBody under “Help ->Contents”.
> > The “Getting started with AnyScript” will answer some of your
> > questions about mass, inertia etc.
> >
> > The driving torque is defined in the
> file “BikeFramesAndWheel.any”,
> > the object named “CrankMoment” defines the variation of the
> > crankmoment as a function of the pedalangle.
> >
> >
> > Best regards
> > SÃ¸ren, AnyBody Support
> >
> > — In anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> <mailto:anyscript%
> 40yahoogroups.com> , “nina_rama2002”
> > <nesreen.aboulkhair@> wrote:
> > >
> > > Hi every one in anybody group,
> > >
> > > I’m new to this group and i am facing some confusion in
> > understanding
> > > the Bike Mode. Actually i have successfully run it but i
needed
> to
> > > understand more about the parameters used in this model the
Mass
> > > Inertia of the bone, Muscles, Length of it and the calculation
> of
> > > joint forces and the joint tork against the trank???
> > > Driving tork.
> > > Thanks
> > > Nina
> > >
> >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

Dear SÃ¸ren ,

I appreciate your help and cooperation but i have another question if you do not
mind. I want to know if the knee model you have do include the contact ratio
between the surface of the knee and the joints ?

Thank you In Advance and with my Best Regards

## Nesreen Aboulkhair PhD Research Student.

From: anyscript@yahoogroups.com on behalf of AnyBody Support
Sent: Thu 11/9/2006 9:17 AM
To: anyscript@yahoogroups.com
Subject: [anyscript] Re: Knee Model

Hi Nesreen

If you use the Leg3d model you can find the knee in the file
Brep/aalborg/Leg3d/Jnt.any

The knee is made as a revolute joint, you can find it in the model
tree in HumanModel.Right.Leg.Jnt.Knee

In this joint you can find its reaction by clicking on the
Constraints.Reaction. Since it is a revolute joint there are 5
reactions three forces and two moments, they are given in the
coordinate system of the first node of the joint.

Best regards
SÃ¸ren AnyBody Support

## — In anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com> , “Nesreen Aboulkhair” <nesreen.aboulkhair@…> wrote: > > Dear Soren, > > I have looked through the bike model and i have come up with the main criteria i needed to know and i am now concentrating on the Knee model i want to know some information about the model and the forces acting on the knee? > Please if you can provide me with any information concerning the knee i will appreciate it. > > Thank you In Advance and with my Best Regards > > > ----------------------------------------------------------

> Nesreen Aboulkhair
> PhD Research Student.
> Office 309b
> Howell Building
> School of Engineering and Design
> Brunel Univesristy
> Uxbridge
> Middlesex
> UB8 3PH
> UK
> Tel: +44 1895 267 200
> Email: Nesreen.Aboulkhair@… <mailto:Nesreen.Aboulkhair@…?> ?
> --------------------------------------------------------
>
> ________________________________
>
> From: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com> on
behalf of AnyBody Support
> Sent: Mon 10/30/2006 12:52 PM
> To: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
> Subject: [anyscript] Re: Bike Model 3D
>
>
>
> Hi Nina
>
> If you look in the Tutorial “Getting started with AnyScript”
> (Not “Getting started”) Lesson 2 there is a description on how the
> masses and inertia is defined. You can also look at the
> tutorial “The Mechanical Elements” Lesson 1.
>
> There is also a tutorial which is based on a 2d bike model, so you
> might be able to find some of the abbrevations there this is in
> the “Parameter studies and Optimization” Lesson 1.
>
> RPM means rounds per min.
>
>
> Best regards
> SÃ¸ren, AnyBody Support
>
> — In anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
<mailto:anyscript%
40yahoogroups.com> , “Nesreen Aboulkhair”
> <nesreen.aboulkhair@> wrote:
> >
> > Thank you for replying. but i found some of the terms in the
> script are not clear such as RPM? in the bike model so can you
guide
> a bit further please on where i should find the abbreviations
> meanings. I have looked through the “Getting started” but i could
> not find any thing to answer my question about the mass inertia.
> >
> >
> > Nina
> > ----------------------------------------------------------
> -
> >
> >
> > ________________________________
> >
> > From: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
<mailto:anyscript%
40yahoogroups.com> on behalf of AnyBody Support
> > Sent: Mon 10/30/2006 11:46 AM
> > To: anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
<mailto:anyscript%
40yahoogroups.com>
> > Subject: [anyscript] Re: Bike Model 3D
> >
> >
> >
> > Hi Nina
> >
> > I think it will be a good idea to run some of the tutorials, you
> can
> > find them in the menu of AnyBody under “Help ->Contents”.
> > The “Getting started with AnyScript” will answer some of your
> > questions about mass, inertia etc.
> >
> > The driving torque is defined in the
> file “BikeFramesAndWheel.any”,
> > the object named “CrankMoment” defines the variation of the
> > crankmoment as a function of the pedalangle.
> >
> >
> > Best regards
> > SÃ¸ren, AnyBody Support
> >
> > — In anyscript@yahoogroups.com <mailto:anyscript%40yahoogroups.com>
<mailto:anyscript%
40yahoogroups.com> <mailto:anyscript%
> 40yahoogroups.com> , “nina_rama2002”
> > <nesreen.aboulkhair@> wrote:
> > >
> > > Hi every one in anybody group,
> > >
> > > I’m new to this group and i am facing some confusion in
> > understanding
> > > the Bike Mode. Actually i have successfully run it but i
needed
> to
> > > understand more about the parameters used in this model the
Mass
> > > Inertia of the bone, Muscles, Length of it and the calculation
> of
> > > joint forces and the joint tork against the trank???
> > > Driving tork.
> > > Thanks
> > > Nina
> > >
> >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

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

Hi Nesreen

The current knee model is made a simple revolute joint(hinge) so it
do not take into account the surface shape of the bones. The joint
has the following reactions.

3 forces x,y,z
2 moments mx,my (as i recall it the z axis is the free one)

It is possible to do other kinds of knee models in the system,

http://www.anybody.aau.dk/pdf/EshuisKnee.pdf

This model uses a four bar linkage to control the kinematics.

Best regards
SÃ¸ren

## — In anyscript@yahoogroups.com, “Nesreen Aboulkhair” <nesreen.aboulkhair@…> wrote: > > Dear SÃ¸ren , > > I appreciate your help and cooperation but i have another question if you do not mind. I want to know if the knee model you have do include the contact ratio between the surface of the knee and the joints ? > > Thank you In Advance and with my Best Regards > > > -------------------------------------------------------------------

> Nesreen Aboulkhair
> PhD Research Student.
> --------------------------------------------------------
>
> ________________________________
>
> From: anyscript@yahoogroups.com on behalf of AnyBody Support
> Sent: Thu 11/9/2006 9:17 AM
> To: anyscript@yahoogroups.com
> Subject: [anyscript] Re: Knee Model
>
>
>
> Hi Nesreen
>
> If you use the Leg3d model you can find the knee in the file
> Brep/aalborg/Leg3d/Jnt.any
>
> The knee is made as a revolute joint, you can find it in the model
> tree in HumanModel.Right.Leg.Jnt.Knee
>
> In this joint you can find its reaction by clicking on the
> Constraints.Reaction. Since it is a revolute joint there are 5
> reactions three forces and two moments, they are given in the
> coordinate system of the first node of the joint.
>
> Best regards
> SÃ¸ren AnyBody Support
>
> — In anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> , “Nesreen Aboulkhair”
> <nesreen.aboulkhair@> wrote:
> >
> > Dear Soren,
> >
> > I have looked through the bike model and i have come up with the
> main criteria i needed to know and i am now concentrating on the
> Knee model i want to know some information about the model and the
> forces acting on the knee?
> > Please if you can provide me with any information concerning the
> knee i will appreciate it.
> >
> > Thank you In Advance and with my Best Regards
> >
> >
> > ----------------------------------------------------------
> -
> > Nesreen Aboulkhair
> > PhD Research Student.
> > Office 309b
> > Howell Building
> > School of Engineering and Design
> > Brunel Univesristy
> > Uxbridge
> > Middlesex
> > UB8 3PH
> > UK
> > Tel: +44 1895 267 200
> > Email: Nesreen.Aboulkhair@ <mailto:Nesreen.Aboulkhair@?> ?
> > --------------------------------------------------------
> >
> > ________________________________
> >
> > From: anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> on behalf of AnyBody Support
> > Sent: Mon 10/30/2006 12:52 PM
> > To: anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com>
> > Subject: [anyscript] Re: Bike Model 3D
> >
> >
> >
> > Hi Nina
> >
> > If you look in the Tutorial “Getting started with AnyScript”
> > (Not “Getting started”) Lesson 2 there is a description on how
the
> > masses and inertia is defined. You can also look at the
> > tutorial “The Mechanical Elements” Lesson 1.
> >
> > There is also a tutorial which is based on a 2d bike model, so
you
> > might be able to find some of the abbrevations there this is in
> > the “Parameter studies and Optimization” Lesson 1.
> >
> > RPM means rounds per min.
> >
> >
> > Best regards
> > SÃ¸ren, AnyBody Support
> >
> > — In anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> <mailto:anyscript%
> 40yahoogroups.com> , “Nesreen Aboulkhair”
> > <nesreen.aboulkhair@> wrote:
> > >
> > > Thank you for replying. but i found some of the terms in the
> > script are not clear such as RPM? in the bike model so can you
> guide
> > a bit further please on where i should find the abbreviations
> > meanings. I have looked through the “Getting started” but i
could
> > not find any thing to answer my question about the mass inertia.
> > >
> > >
> > > Nina
> > > ----------------------------------------------------------
> > -
> > >
> > >
> > > ________________________________
> > >
> > > From: anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> <mailto:anyscript%
> 40yahoogroups.com> on behalf of AnyBody Support
> > > Sent: Mon 10/30/2006 11:46 AM
> > > To: anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> <mailto:anyscript%
> 40yahoogroups.com>
> > > Subject: [anyscript] Re: Bike Model 3D
> > >
> > >
> > >
> > > Hi Nina
> > >
> > > I think it will be a good idea to run some of the tutorials,
you
> > can
> > > find them in the menu of AnyBody under “Help ->Contents”.
> > > The “Getting started with AnyScript” will answer some of your
> > > questions about mass, inertia etc.
> > >
> > > The driving torque is defined in the
> > file “BikeFramesAndWheel.any”,
> > > the object named “CrankMoment” defines the variation of the
> > > crankmoment as a function of the pedalangle.
> > >
> > >
> > > Best regards
> > > SÃ¸ren, AnyBody Support
> > >
> > > — In anyscript@yahoogroups.com <mailto:anyscript%
40yahoogroups.com> <mailto:anyscript%
> 40yahoogroups.com> <mailto:anyscript%
> > 40yahoogroups.com> , “nina_rama2002”
> > > <nesreen.aboulkhair@> wrote:
> > > >
> > > > Hi every one in anybody group,
> > > >
> > > > I’m new to this group and i am facing some confusion in
> > > understanding
> > > > the Bike Mode. Actually i have successfully run it but i
> needed
> > to
> > > > understand more about the parameters used in this model the
> Mass
> > > > Inertia of the bone, Muscles, Length of it and the
calculation
> > of
> > > > joint forces and the joint tork against the trank???
> > > > Driving tork.
> > > > Thanks
> > > > Nina
> > > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

Hi,

I am a new user of ANYBODY and i have several queries on the
capabilities of ANYBODY. My goal is ultimately to calculate knee
joint forces and finding the respective muscle/ligament/tendon
forces in a particular action.

Firstly, regarding the creation of ligaments, I understand that
there are no ligaments input at the knee joint in the current model
of ANYBODY. Am I right? But users are able to input their own
ligaments as seen from the tutorial on the ligaments, but i was
wondering if there is an interface for me to put in a characteristic
force equation of the ligaments into the model? Also, am I able to
state explicitly the position of the ligaments by the pennation
angle, the insertion and attachment points? Regarding the attachment
and insertion points for muscles/ligaments/tendons, which coordinate
system are they referenced to? Also, I would like to know if it’s
possible to link the mocap global coordinate system with that of the
model’s coordinate system, how? and if this will affect the
definition of the positioning of the bones/muscles in any way? Also,
regarding external forces, is it possible to input exactly, the
position, direction and magnitude of any external force (provided
that the centre of pressure is known from the mocap system)?

Hope to hear from you soon! Thank you.

Regards,
May

Hi May

Welcome to the group

It is correct that there are no ligaments in the current knee model.

If you want to use another function for defining the strength of the
ligaments than the one used by the default ligaments this is
possible. This can be done by using an AnyForce object here is a
small skecth

AnyKinPline ligament={
AnyRefNode &ref1= …originnode;
AnyRefNode &ref1= …insertationnode
};

AnyForce LigamentForce ={
F=-.ligament.Pos^2*0.0001; //some arbitary function depending on
the length of the ligament!
AnyKinPline &ref=.ligament; //reference to the object to apply the
force on.
};

In the function above you can also make use of if sentences so that
you can create a slack length. Please see the “iffun” in the manual
for the details.

I am not sure i understand the question about the pennation angle?

The insertation and origin points of the ligaments are defined as
AnyRefNode nodes on the respective segments. These nodes are defined
in the local cooridnate system of these segments.

Regarding the coordinate system of the mocap system i am not sure i
understand the question, i will try to explain how it works.

The mocap system will record the data using its own coordinate
system. When creating an AnyBody model based on these data you will
use the same cooridnate system as reference so the recorded markers
will move in space like they where recorded. The next step is then
to “hook” the model up to specific coordinates of those markers.
Please see the webcast “Gait Modeling” for the details on how to do
this.

http://www.anybodytech.com/196.html

If you have recorded the forces in the experiment it is possible to
apply those directly to the right location on the foot. Please see
the /arep/aalborg/Gait3D model as an example of this.

Best regards
SÃ¸ren, AnyBody Support

— In anyscript@yahoogroups.com, “may1234507” <amei_yeah@…> wrote:
>
> Hi,
>
> I am a new user of ANYBODY and i have several queries on the
> capabilities of ANYBODY. My goal is ultimately to calculate knee
> joint forces and finding the respective muscle/ligament/tendon
> forces in a particular action.
>
> Firstly, regarding the creation of ligaments, I understand that
> there are no ligaments input at the knee joint in the current
model
> of ANYBODY. Am I right? But users are able to input their own
> ligaments as seen from the tutorial on the ligaments, but i was
> wondering if there is an interface for me to put in a
characteristic
> force equation of the ligaments into the model? Also, am I able to
> state explicitly the position of the ligaments by the pennation
> angle, the insertion and attachment points? Regarding the
attachment
> and insertion points for muscles/ligaments/tendons, which
coordinate
> system are they referenced to? Also, I would like to know if it’s
> possible to link the mocap global coordinate system with that of
the
> model’s coordinate system, how? and if this will affect the
> definition of the positioning of the bones/muscles in any way?
Also,
> regarding external forces, is it possible to input exactly, the
> position, direction and magnitude of any external force (provided
> that the centre of pressure is known from the mocap system)?
>
> Hope to hear from you soon! Thank you.
>
> Regards,
> May
>