AnyForceMomentMeasure2

Archive AnyScript Yahoo archive
1

Hello,
I have a couple of questions regarding AnyForceMomentMeasure2. I’m trying to
calculate the hip moments in the GaitVaughn model. I’ve looked at post 2117 and
the code for finding the moment at the ankle. This is the code that Sebastian
gave:
AnyForceMomentMeasure2 AnkleJnt =
{
AnyRefNode &ref = Main.HumanModel.BodyModel.Right.Leg.Seg.Shank.AnkleJoint;
//pt of interest
AnySeg &ref1 = Main.HumanModel.BodyModel.Right.Leg.Seg.Shank;//all force
components acting on this segment will be considered
AnyForceBase &ref3 =
Main.HumanModel.BodyModel.Right.Leg.Jnt.Ankle.Constraints.Reaction;//force base
};

I know that this works for the ankle, but I can’t seem to get something similar
to work for the hip. I tried this code for the hip, but it results in a moment
that is really close to 0.

 AnyForceMomentMeasure2 HipJnt2 =

{
AnyRefNode &ref = Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh.HipJoint;
//pt of interest
AnySeg &ref1 = Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh;//all force
components acting on this segment will be considered
AnyForceBase &ref3 =
Main.HumanModel.BodyModel.Right.Leg.Jnt.Hip.Constraints.Reaction;//force base
};

I also tried including the pelvis segment and naming all of the muscles
individually instead of using the reaction force, and the result is better, but
the entire moment is positive, and I should be getting a flexor moment
mid-cycle.

Could anyone tell me where I am going wrong?

Thanks,
Abra

2

Hi Abra,

The mentioned code will actually give the moments created by the reaction
forces of the joint because no muscles are listed. I assume you want the
moment created by the muscles around the hip. So you have to list all the
leg muscles and also all the segments from the hip down to the foot : thigh,
shank and foot (it is actually a free body diagram where you have to list
all component on one side of the cut).

Hopefully the muscle list already exist (it is quite long) in
…\Body\AAUHuman\Leg\LegMuscleNames. Please notice that the psoas are not
listed yet and should be added for proper result. There is also a file
containing the definition of moment measures for the leg in
…\Body\AAUHuman\Leg\LegMoments that you can use.

The code looks like this:

AnyForceMomentMeasure2 HipNetMomentMuscle = {

AnyRefNode &ref = …HipNodeRef.RotNode;

AnySeg &seg1=…Seg.Shank;

AnySeg &seg2=…Seg.Foot;

AnySeg &seg3=…Seg.Thigh;

#include “…\Body\AAUHuman\Leg\LegMuscleNames.any”

};

Best regards,

Sylvain, AnyBody Support

From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of ens.abra
Sent: 13. marts 2009 18:35
To: anyscript@yahoogroups.com
Subject: [AnyScript] AnyForceMomentMeasure2

Hello,
I have a couple of questions regarding AnyForceMomentMeasure2. I’m trying to
calculate the hip moments in the GaitVaughn model. I’ve looked at post 2117
and the code for finding the moment at the ankle. This is the code that
Sebastian gave:
AnyForceMomentMeasure2 AnkleJnt =
{
AnyRefNode &ref = Main.HumanModel.BodyModel.Right.Leg.Seg.Shank.AnkleJoint;
//pt of interest
AnySeg &ref1 = Main.HumanModel.BodyModel.Right.Leg.Seg.Shank;//all force
components acting on this segment will be considered
AnyForceBase &ref3 =
Main.HumanModel.BodyModel.Right.Leg.Jnt.Ankle.Constraints.Reaction;//force
base
};

I know that this works for the ankle, but I can’t seem to get something
similar to work for the hip. I tried this code for the hip, but it results
in a moment that is really close to 0.

AnyForceMomentMeasure2 HipJnt2 =
{
AnyRefNode &ref = Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh.HipJoint;
//pt of interest
AnySeg &ref1 = Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh;//all force
components acting on this segment will be considered
AnyForceBase &ref3 =
Main.HumanModel.BodyModel.Right.Leg.Jnt.Hip.Constraints.Reaction;//force
base
};

I also tried including the pelvis segment and naming all of the muscles
individually instead of using the reaction force, and the result is better,
but the entire moment is positive, and I should be getting a flexor moment
mid-cycle.

Could anyone tell me where I am going wrong?

Thanks,
Abra

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

3

Hi Sylvain,
Thank you for clarifying the issue. I appreciate your help!
~Abra

— In anyscript@yahoogroups.com, AnyScript Support <anyscriptsup@…> wrote:
>
> Hi Abra,
>
>
>
> The mentioned code will actually give the moments created by the reaction
> forces of the joint because no muscles are listed. I assume you want the
> moment created by the muscles around the hip. So you have to list all the
> leg muscles and also all the segments from the hip down to the foot : thigh,
> shank and foot (it is actually a free body diagram where you have to list
> all component on one side of the cut).
>
> Hopefully the muscle list already exist (it is quite long) in
> …\Body\AAUHuman\Leg\LegMuscleNames. Please notice that the psoas are not
> listed yet and should be added for proper result. There is also a file
> containing the definition of moment measures for the leg in
> …\Body\AAUHuman\Leg\LegMoments that you can use.
>
>
>
> The code looks like this:
>
>
>
> AnyForceMomentMeasure2 HipNetMomentMuscle = {
>
> AnyRefNode &ref = …HipNodeRef.RotNode;
>
>
>
> AnySeg &seg1=…Seg.Shank;
>
> AnySeg &seg2=…Seg.Foot;
>
> AnySeg &seg3=…Seg.Thigh;
>
> #include “…\Body\AAUHuman\Leg\LegMuscleNames.any”
>
> };
>
>
>
>
>
> Best regards,
>
> Sylvain, AnyBody Support
>
>
>
>
>
> _____
>
> From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
> Of ens.abra
> Sent: 13. marts 2009 18:35
> To: anyscript@yahoogroups.com
> Subject: [AnyScript] AnyForceMomentMeasure2
>
>
>
> Hello,
> I have a couple of questions regarding AnyForceMomentMeasure2. I’m trying to
> calculate the hip moments in the GaitVaughn model. I’ve looked at post 2117
> and the code for finding the moment at the ankle. This is the code that
> Sebastian gave:
> AnyForceMomentMeasure2 AnkleJnt =
> {
> AnyRefNode &ref = Main.HumanModel.BodyModel.Right.Leg.Seg.Shank.AnkleJoint;
> //pt of interest
> AnySeg &ref1 = Main.HumanModel.BodyModel.Right.Leg.Seg.Shank;//all force
> components acting on this segment will be considered
> AnyForceBase &ref3 =
> Main.HumanModel.BodyModel.Right.Leg.Jnt.Ankle.Constraints.Reaction;//force
> base
> };
>
> I know that this works for the ankle, but I can’t seem to get something
> similar to work for the hip. I tried this code for the hip, but it results
> in a moment that is really close to 0.
>
> AnyForceMomentMeasure2 HipJnt2 =
> {
> AnyRefNode &ref = Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh.HipJoint;
> //pt of interest
> AnySeg &ref1 = Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh;//all force
> components acting on this segment will be considered
> AnyForceBase &ref3 =
> Main.HumanModel.BodyModel.Right.Leg.Jnt.Hip.Constraints.Reaction;//force
> base
> };
>
> I also tried including the pelvis segment and naming all of the muscles
> individually instead of using the reaction force, and the result is better,
> but the entire moment is positive, and I should be getting a flexor moment
> mid-cycle.
>
> Could anyone tell me where I am going wrong?
>
> Thanks,
> Abra
>
>
>
>
>
> [Non-text portions of this message have been removed]
>