The APAS with Markers Sets Systems


Dear Mr. Tabakin,

It is very nice to mail you.  You seem to plan  a useful study for clinical
gait analysis.
I am a Korean(South) physiatrist(Doctor of rehabilitation medicine). I am
studying clinical 3D gait analysis with APAS(ariel performance analysis
system) interfaced to matlab. I use Helen Hayes marker set and I calculate
the kinematics with my own method which is based on Grood and Suntay's
Nonorthogonal Joint Coordination System(floating axis). Actually, I made a
modification to the HH marker set with an aim of estimating the joint center
better. I think I should study to determine the modification would be really
better than the original one.

Could I participate in your study? Or would you kindly share the experience
with me?
I would like to inform you that I have only kinematic data because I do not
have a forceplate yet.

Although he may not remember me, I know your professor via email
communication. It was like a brief distant learning and he was very kind to
teach me.
Before I use the HH marker set, I tried his marker set on the "Dynamics of
human gait".
But I gave up his marker set because
   1. We have only 4 cameras which is not enough to cover the Vaughan
marker set - he wanted to call it CCC marker set.
   2. His marker set "seems" not to be as good as HH to apply on wide range
of anthropometry. It is only "seems". I do not have any scientific data on
this assumption.
You may have more ideas on this point.

Sincerely yours,

Sun G. Chung M.D., Ph.D.
Dept Rehab Medicine
Seoul National University, College of Medicine
YeonGeon Dong 28, ChongRo Gu
Seoul Korea
(T) 82-2-760-3954, 760-2619
(F) 82-2-743-7473

-----?? ???-----
?? ??: Dudley Tabakin <>
?? ??: Multiple recipients of list CGA <>
??: 1999? 7? 16? ??? ?? 2:36
??: Gait Analysis Software

Hello all Gait Analysis Laboratories,

I am an MSc student at the University of Cape Town in South Africa,
working under the direction of Professor Kit Vaughan. My thesis
research involves a comparison of different gait analysis software
packages to determine whether the results obtained from one can be
compared with those of another. The research will not assess whether
one package is better than another, but rather will compare the
results. The results obtained from the various gait analysis models
are often used in clinical assessments of pathological gait and
decisions on operative intervention. However, different models
obviously use slightly different mathematical methods.

I plan to gather 3D kinematic and force plate data on a set of normal
subjects. I will be using the Helen Hayes Hospital marker set with 15
markers. The primary format for these data will be C3D but it will, of
course, be possible to transform the data into other formats. (e.g.
the DST format, advocated by CAMARC). I would then like to feed the
same set of data into different packages and compare the kinematic
(primarily sagittal joint angles) and kinetic (primarily joint
moments) data. Oxford Metrics and Peak Performance have already
offered me temporary use of their gait analysis software packages and
I am hoping that I will also be able to process my data using the
QGait package from Qualisys and Orthotrak II package from Motion
Analysis Corporation.

I am therefore interested in hearing from you if you are using either
QGait or Orthotrak. The best way that my analysis could be
accomplished would probably be for me to send my data to you and you
pass it through your program and return it to me. I realise that this
is a sensitive issue, and I wish to emphasize that this is purely an
academic project. The results will, I believe, be of benefit to all
those involved in clinical gait analysis.

I look forward to your advice.

Yours sincerely

Dudley Tabakin
Gait Laboratory
University of Cape Town
Sport Science Institute of South Africa
Cape Town
South Africa
Tel: +27 21 686 7330 ext. 257

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