No announcement yet.

Marker sets and models for the kinematic analysis of amputees(#025940) - summary of responses

This topic is closed.
  • Filter
  • Time
  • Show
Clear All
new posts

  • Marker sets and models for the kinematic analysis of amputees(#025940) - summary of responses

    Dear Biomch-L subscribers,

    Thanks to all for your helpful responses to my post on the above subject
    (see below for original post) and apologies for the delay in sending
    this in. I have compiled a summary of responses below from those happy
    to have their messages posted. Also pls refer to #025983 for additional
    response from Allan Carman (many thanks!).

    There was agreement amongst several respondents that the marker set and
    model employed should be chosen to reflect the outcome measures of
    interest, and a general indication of preference for segment based 6DOF
    modelling with functional estimations of joint centres of rotation in
    this context.

    There does not appear to be any standard protocol for placement on lower
    limb prosthetic components, particularly those that do not resemble
    anatomical counterparts either cosmetically or functionally (e.g.
    running blades, energy store and release feet, SACH feet,
    shock-absorbing pylons). The outcome-measure driven approach to
    selecting landmarks certainly seems most appropriate, rather than trying
    to exploit a generic model that cannot describe what's going on
    functionally, but this limits comparison against other data sets both
    within centre and across institutions.

    Inter-limb kinematic comparisons (e.g. in the case of unilateral
    amputees) are complicated in that you may be trying to compare two
    systems that are geometrically and/or functionally different for a start
    and any analysis from extracted data must account for this (a simple
    example would be comparing peak transverse rotations from 6DOF data from
    a sound thigh segment and a prosthetic one that is NOT subject to soft
    tissue artefact). Zero conditions are particularly difficult to
    establish with the different limb geometries/mechanisms and alignments
    (these may be under investigation themselves).

    I have been keen to explore the use of landmark-based 3D motion capture
    for amputee assessment in a clinical context due to the lack of outcome
    measures for higher activity amputee cohorts.

    However, given the above issues on top of the general issues of
    reliability of the method as a whole (pls see /?for a very useful
    summary of this) maybe its application should be restricted to isolated
    cases of interest where a higher level of control can be imposed, rather
    than routine clinical work. ie. I should compromise on my generic model
    and avoid /?comparing outside the context of the individual patient. I
    haven't even begun to consider moments, powers and energy transfer

    Thanks once again for your input on this.

    Kind regards



    Dear Jenny Kent,

    I am Pietro Garofalo. I spent my PhD activities at INAIL Prostheses
    Centre (Bologna, Italy) dealing with exactly the same problems you
    explained in your post.

    Therefore it was very easy for me to understand your opinions, both for
    the analysis of kinematics and kinetics.

    I also definitely agree with you that all the research around amputee
    should start from which is the clinical questions to answer to.

    For this reason I would like to inform you that I recently completed my
    PhD thesis in which, from one side, specific protocols were defined for
    the analysis of amputees using stereophotogrammetry and, from the other
    side, alternative solutions (in which also functional method are
    involved) based on inertial sensors were proposed.

    I am now in fact in Xsens Technologies B.V. and together with INAIL
    Prostheses Centre the above research is still going on.

    In particular, a protocol was recently proposed by for the 3D kinematics
    measurements of gait analysis adopting inertial sensors.

    See .

    I invite you to contact Andrea Giovanni Cutti from INAIL Prostheses
    Centre from which everything started and then, if you are interested, as
    soon as my thesis will be printed out, you may receive a copy of it.

    You can also have the possibility to meet Mr. Cutti at ISPO 2010
    (Leipzig) on next May in which the application of the above protocol on
    above-knee amputees received an oral presentation.

    Of course I am open to further discussions (I really would like to
    discuss on Biomech-L about this topic, which is still, in my opinion,
    far from being established among the community).

    Pietro Garofalo

    Technical Product Manager - Movement Science

    Xsens - 10 Years in Motion


    Dear Jenny Kent, I've been struggling on similar sorts of issues as
    well, looking at amputees and patients wearing knee orthosis. We are
    exploiting the recent protocol we've published recently (Leardini et al.
    Gait Posture.

    2007 Oct;26(4):560-71), also encouraged by a following quantitative
    comparison (Ferrari et al Gait Posture. 2008 Aug;28(2):207-16), and a
    recent study (under review) where relevant inter-session and
    inter-examiner repeatability was found better than previous reports.
    I've no solutions for you at the moment, but just these readings for
    your knowledge. Do not hesitate for any further information.

    Very kind regards,

    ************************************************** *******************

    Alberto Leardini

    ************************************************** *******************


    My experience is in trying to build a functional anthropometric model to
    use with CAD systems for design of worker/operator environments. While
    reading of your efforts, I wondered if data has been collected on
    pre-amputee subjects which could then be coordinated with post-amputee
    subjects. I realize this may not be practical since, most likely, the
    amputee most likely had a debilitating condition or injury that
    necessitated the amputation. Knowing that a pre-amputee subject will
    undergo amputation, one could place markers as necessary to provide
    comparable locations for measurement post-amputation. I don't know if
    this is of any value to you, but it did occur to me as I read your

    As to a uniform data collection, I would envision markers located on
    torso, pelvis, upper leg, lower leg, and foot. These would not just be
    at the joints, but at equally spaced distances between the joints. In
    this way you be able to track markers in images that would be consistent
    across subjects. The difficult part is determining what locations and
    how to consistently locate them. The soft tissue placement is of course
    a most difficult complication to making measures consistent.

    One of the issues I repeatedly encountered while attempting to build CAD
    manikins was the lack of consistent data collection. The landmarks were
    always pretty well defined, but the authors rarely collected all the
    same ones making the collation of data nearly impossible. Not all the
    necessary data involved the markers, but involved other measures such as
    age, height, and weight associated with each individual set of markers
    and data collected. Again, none of this may be of use to you.

    Hopefully, these anecdotal comments may suggest some paths of

    Good luck in your endeavors.

    Charles Gidcumb

    Human Engineering

    The Boeing Company


    In the end any marker set will give you the appropriate data about the
    movement of the prosthesis, the question of the rotation of the foot
    segment/knee segment is where the axes are and hence where you would
    place the coordinate system.

    Functional joint centres will help to some point but using a segment
    based system is likely to be more fruitful than a HH based system. It
    really depends on what your primary outcome measures for the gait data

    Richard Jones

    Senior Lecturer in Clinical Biomechanics / Director of the Salford Gait
    laboratory Directorate of Prosthetics & Orthotics and Podiatry




    Dear Biomch-L subscribers,

    I'm doing some work on the use of biomechanical models and marker sets
    to study the kinematics of lower limb amputees. My efforts were
    initially geared towards selecting an appropriate marker set for amputee
    analysis that could also be applied broadly to all patient groups and
    healthy subjects (as normative controls) to facilitate comparison, with
    both clinical and research applications in mind. This would comprise a
    standard configuration that could be built upon for specific
    applications that require additional segments/parameters to be analysed,
    but would ensure data collection uniformity as far as possible.

    A lit search I conducted brought up many studies on individual amputees
    or amputee cohorts using a variety of marker sets, although the majority
    appeared to be some form of Helen Hayes derivative. On the prosthetic
    side markers were commonly placed on mechanical centres of rotation
    where obvious (e.g. on single axis joints) or "estimated from the sound

    I was concerned about the appropriateness of the use of several of the
    common models and methods when analysing amputee function, particularly
    when directly comparing the function/movement of prosthetic and sound
    limbs. Examples of such applications would be comparing prosthetic gait
    to normative data, evaluating limb symmetry (is this appropriate
    anyway?! I'm doubtful in most cases, esp when it concerns unilateral
    amputees), and comparing components that function differently
    mechanically (e.g. 4-bar knee vs single axis knee, SACH foot vs foot
    with articulated ankle joint).

    I imagine it may be possible to achieve more reliable/valid results (and
    a system that may be applied more universally) with joint centres
    determined functionally, technical markers for tracking segmental
    movement and perhaps the addition of extra markers to monitor relative
    movement of the residual limb with respect to the socket (although I
    won't even attempt to touch on the issues of placement and treatment of
    soft tissue artefact here..). Regarding the selection/development of a
    model that will enable prosthetic components that have not been designed
    to reproduce natural segment movement to be adequately represented (e.g.
    SACH foot, running blades) and that will allow different limb alignments
    to be compared (where the neutral condition at joints may be altered by
    nature of the study) I am a little lost. I anticipate when I begin to
    consider the analysis of joint moments, torques and powers, which
    undoubtedly will open yet another can of worms, I will be even more so.

    I suspect that my idea of a universally applied base marker set and
    model may be unrealistic, even given an allowance for additional
    markers/segments for specific analyses, and that with amputee cohorts
    kinematic models will have to be more specifically geared towards the
    question that the analysis is required to answer.

    I would be very grateful if anyone has any thoughts or advice to share
    on the subject. I remember there was a very relevant presentation and
    discussion at the CMAS UKI annual meeting and conference in Edinburgh
    2009 - I am aware that there may be groups specifically looking into it
    and I was wondering if there have been any recent developments that I
    have not come across. I'll happily post a summary of replies - please
    let me know if you'd prefer not to appear in it!

    Many thanks

    Jenny Kent

    Higher Scientific Officer

    Centre for Human Performance, Rehabilitation and Sports Medicine DMRC
    Headley Court Epsom, Surrey UK