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Dear All,
Responses to my query about the definition of joint neutrals when
displaying intersegmental angles drew quite a few replies, basically
confirming that there is, as yet no standard.
Thanks to Vaughan Klippers for drawing my attention to the Phys. Ther.
paper, in which the pelvic axis is defined by using the anterior and
posterior superior iliac spines, and 10 degrees (ASIS lower than PSIS)
found to be the "normal neutral" position. I guess this is about as close
as we have to a standard at present. Or does someone disagree...?
Many thanks for your help once again.
Chris
...........
=46rom: V.Kippers@mailbox.uq.oz.au (Vaughan Kippers)
Day et al. (Effect of pelvic tilt on standing posture. Physical Therapy
64(4):510-516, 1984) used PSIS (S2) and ASIS to define pelvic posture and
found a mean angle of 10 degrees of "anterior pelvic tilt" to be normal. I
have used these same landmarks to distinguish between hip and vertebral
motion in the sagittal plane.
Please contact me if you require any more information.
Vaughan
I am sorry to say I have no answers to offer, but I am also interested in th=
is
question, as our laboratory is very involved in investigating human kinemati=
cs
and dynamics in the absence of gravity (i.e., space). Would you be good eno=
ugh
to post your responses? Thank you in advance --
Juliannne Zimmerman
University of Maryland
Space Systems Laboratory
jaz@ssl.umd.edu
=46rom: "Thomas G. Loebig"
We are investigating pelvic strain in human cadavers associated with total
hip arthoplasty. According to Grant's Atlas of Anatomy, the ASIS and PS lie
in the same vertical plane. In the coronal plane, the L-R iliac crests are
naturally aligned in the same horizontal plane. For the femur in single-leg
stance, the femoral neck is anteverted 15=B0 from the greater trochanter, an=
d
the femoral shaft is flexed 10=B0 from vertical and abducted 12=B0 relative =
to
the pelvis. The reference that these femoral angles came from is MIA, I
think a student has it, and is an unpublished manuscript which led to me to
the actual source. I'll find it if you need it, and if you get some leads,
let me know. I've also been told that Pawells (sp?) did some early work.
Good Luck.
Tom
=46rom: "Thomas M. Greiner"
I, too, am not aware of any standards for defining hip joint positions.
But, here's how I did it for my research.
=46irst, I defined a standard orientation system based upon landmarks in
the pelvic girdle. The sagital plane is defined as the plane running
through the points: Proximal End of the Sacral Crest -- Distal End of
the Sacral Crest -- Top of Pubic Symphysis. Once that plane is
established, the crononal plane is defined as the plane running through
the points: Anterior Superior Iliac Spine -- Top of Pubic Symphysis.
With those two planes defined, the transverse plane remains as the plane
that is mutually perpendicular to the other two.
The position of the hip joint is defined based upon a reference to these
planes. Two thigh reference lines are created -- one being the axis of
the femoral shaft, and the other being the line that joins the distal
most points of the medial and lateral femoral condyles.
Now that references are established, I define hip joint position as
follows:
=46lexion/Extension -- Angle between the Femoral Axis and the Coronal
Plane, when viewed in the sagital plane. 0 degrees
of flexion is when the two lines are parallel.
Rotation -- Angle between the Condylar Line and the Sagital
plane, when viewed in the transverse plane. 0 degrees
is when the two lines are perpendicular.
Abduction/Adduction -- Angle between the Condylar Line and the Sagital
plane, when viewed in the coronal plane. 0 degrees is when
the two lines are perpendicular.
I hope this helpful.
=46rom: Ulrich Glitsch
Okay, the actual problem you mentioned is a very common problem
in biomechanics I think. There exists no final general solution
of the joint angles problem as you can see by the great amount
of different approaches and from these derived joint angles
definitions. In my opinion the problem has to be seen from different
points of view:
1) What is the goal of the relevant investigation?
2) Of which complexity the approach must/can be?
3) Which experimental setup is available?
4) To what else the data should comparable?
5) Do you want to exchange data with other labs, software etc?
The European CAMARC (Computer Aided Movement Analysis in Rehabilitation
Context)Consortium made proposals for segments and joint angles
definitions on the basis of Cardan Angles. I can fax you a copy of
this if you like.
On the other hand, if I got your special problem wright, you need not
the absolute 0 angle position of the hip joint but the relative
change from a "'reasonable' Standard position". This position
must be assessed with the same experimental setup as the relevant
trials. We use this very practical approach often in our lab by alining
the posture of a subject to a known reference frame. Often we get
better results with this than with a very theoretical and sophisticated
(sometimes not very anatomical relevant) definition in combination
with a rather simple experimental setup. You have to focus the errors
in finding the relevant antomical lankmarks and other technical points.
So far at this moment
Ulli
__________________________________________________ __________________
Dr. Chris Kirtley MB ChB, PhD c.kirtley@info.curtin.edu.au
^
Lecturer, Bio-engineering --_ / \
/ \
School of Physiotherapy, Perth #_.---._/
Curtin University of Technology, V
GPO Box U1987,
Perth 6001, Tel +61 9 351 3649
Western Australia. Fax +61 9 351 3636
__________________________________________________ __________________
Responses to my query about the definition of joint neutrals when
displaying intersegmental angles drew quite a few replies, basically
confirming that there is, as yet no standard.
Thanks to Vaughan Klippers for drawing my attention to the Phys. Ther.
paper, in which the pelvic axis is defined by using the anterior and
posterior superior iliac spines, and 10 degrees (ASIS lower than PSIS)
found to be the "normal neutral" position. I guess this is about as close
as we have to a standard at present. Or does someone disagree...?
Many thanks for your help once again.
Chris
...........
=46rom: V.Kippers@mailbox.uq.oz.au (Vaughan Kippers)
Day et al. (Effect of pelvic tilt on standing posture. Physical Therapy
64(4):510-516, 1984) used PSIS (S2) and ASIS to define pelvic posture and
found a mean angle of 10 degrees of "anterior pelvic tilt" to be normal. I
have used these same landmarks to distinguish between hip and vertebral
motion in the sagittal plane.
Please contact me if you require any more information.
Vaughan
I am sorry to say I have no answers to offer, but I am also interested in th=
is
question, as our laboratory is very involved in investigating human kinemati=
cs
and dynamics in the absence of gravity (i.e., space). Would you be good eno=
ugh
to post your responses? Thank you in advance --
Juliannne Zimmerman
University of Maryland
Space Systems Laboratory
jaz@ssl.umd.edu
=46rom: "Thomas G. Loebig"
We are investigating pelvic strain in human cadavers associated with total
hip arthoplasty. According to Grant's Atlas of Anatomy, the ASIS and PS lie
in the same vertical plane. In the coronal plane, the L-R iliac crests are
naturally aligned in the same horizontal plane. For the femur in single-leg
stance, the femoral neck is anteverted 15=B0 from the greater trochanter, an=
d
the femoral shaft is flexed 10=B0 from vertical and abducted 12=B0 relative =
to
the pelvis. The reference that these femoral angles came from is MIA, I
think a student has it, and is an unpublished manuscript which led to me to
the actual source. I'll find it if you need it, and if you get some leads,
let me know. I've also been told that Pawells (sp?) did some early work.
Good Luck.
Tom
=46rom: "Thomas M. Greiner"
I, too, am not aware of any standards for defining hip joint positions.
But, here's how I did it for my research.
=46irst, I defined a standard orientation system based upon landmarks in
the pelvic girdle. The sagital plane is defined as the plane running
through the points: Proximal End of the Sacral Crest -- Distal End of
the Sacral Crest -- Top of Pubic Symphysis. Once that plane is
established, the crononal plane is defined as the plane running through
the points: Anterior Superior Iliac Spine -- Top of Pubic Symphysis.
With those two planes defined, the transverse plane remains as the plane
that is mutually perpendicular to the other two.
The position of the hip joint is defined based upon a reference to these
planes. Two thigh reference lines are created -- one being the axis of
the femoral shaft, and the other being the line that joins the distal
most points of the medial and lateral femoral condyles.
Now that references are established, I define hip joint position as
follows:
=46lexion/Extension -- Angle between the Femoral Axis and the Coronal
Plane, when viewed in the sagital plane. 0 degrees
of flexion is when the two lines are parallel.
Rotation -- Angle between the Condylar Line and the Sagital
plane, when viewed in the transverse plane. 0 degrees
is when the two lines are perpendicular.
Abduction/Adduction -- Angle between the Condylar Line and the Sagital
plane, when viewed in the coronal plane. 0 degrees is when
the two lines are perpendicular.
I hope this helpful.
=46rom: Ulrich Glitsch
Okay, the actual problem you mentioned is a very common problem
in biomechanics I think. There exists no final general solution
of the joint angles problem as you can see by the great amount
of different approaches and from these derived joint angles
definitions. In my opinion the problem has to be seen from different
points of view:
1) What is the goal of the relevant investigation?
2) Of which complexity the approach must/can be?
3) Which experimental setup is available?
4) To what else the data should comparable?
5) Do you want to exchange data with other labs, software etc?
The European CAMARC (Computer Aided Movement Analysis in Rehabilitation
Context)Consortium made proposals for segments and joint angles
definitions on the basis of Cardan Angles. I can fax you a copy of
this if you like.
On the other hand, if I got your special problem wright, you need not
the absolute 0 angle position of the hip joint but the relative
change from a "'reasonable' Standard position". This position
must be assessed with the same experimental setup as the relevant
trials. We use this very practical approach often in our lab by alining
the posture of a subject to a known reference frame. Often we get
better results with this than with a very theoretical and sophisticated
(sometimes not very anatomical relevant) definition in combination
with a rather simple experimental setup. You have to focus the errors
in finding the relevant antomical lankmarks and other technical points.
So far at this moment
Ulli
__________________________________________________ __________________
Dr. Chris Kirtley MB ChB, PhD c.kirtley@info.curtin.edu.au
^
Lecturer, Bio-engineering --_ / \
/ \
School of Physiotherapy, Perth #_.---._/
Curtin University of Technology, V
GPO Box U1987,
Perth 6001, Tel +61 9 351 3649
Western Australia. Fax +61 9 351 3636
__________________________________________________ __________________