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Intersegmental joint angles: summary of responses

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  • Intersegmental joint angles: summary of responses

    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.


    =46rom: (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.

    I am sorry to say I have no answers to offer, but I am also interested in th=
    question, as our laboratory is very involved in investigating human kinemati=
    and dynamics in the absence of gravity (i.e., space). Would you be good eno=
    to post your responses? Thank you in advance --

    Juliannne Zimmerman
    University of Maryland
    Space Systems Laboratory

    =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=
    the femoral shaft is flexed 10=B0 from vertical and abducted 12=B0 relative =
    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    think a student has it, and is an unpublished manuscript which led to me to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.


    =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

    =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


    __________________________________________________ __________________
    Dr. Chris Kirtley MB ChB, PhD
    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
    __________________________________________________ __________________