Hello Lina,
Thank you for your message.
Unfortunately, we are not aware of much information comparing the
marker sets. That is why we performed the study you mentioned
below. We used the same subject and same trial to document
that there are significant differences in the results depending
on which marker set is used. Unfortunately, this does not have
much influence if we publish the results since competitors will
state that we are simply trying to sell more systems. It would
be nice if this work could be performed by a third party (independant
lab) and then publish the results.
The APAS is designed to allow the user
to use any marker set they feel is most appropriate. However,
we always recommend that markers only be used for reference.
We have shown that the most accurate results are obtained using
the manual (semi-automatic) digitizing option of the APAS. The
drawback to this is obviously the time required for digitizing.
Many people like the automatic digitizing of markers because they
feel it is faster.
We have also performed time comparison
studies with and without markers. We started timing when the
subject walked in the door. The subject without markers was
recorded as he walked two strides. He was then finished with
his part and we started the capture & digitizing process.
The other subject entered at the same time, however, he needed to
have markers placed on the desired joints (which is time consuming).
The first subject was already being digitized before the second
subject had all the markers placed. The second subject was
then recorded as he walked two strides. At the end of the
study, we found no significant differences in the
"overall" time to perform the analysis.
I hope I helped to answer some of your
questions. Please feel free to contact me for any additional
information.
Sincerely,
John Probe
Ariel Dynamics, Inc.
----- Original Message -----
Sent: Wednesday, January 23, 2002 7:58 AM
Subject: information
Good Morning.
My name is Lina Zapata. I am a last year mechanical
engineering student from Bogota, Colombia, South America. I was
searching the web looking for information about marker sets
(advantages, disadvantages...) for your system, APAS.
I found your page /apasgait/Markers-set-comparison/
with such information but it has not been published yet. I would
like to know when these information is going to be available and if
you can tell me where I can get more information about the subject.
I would highly appreciate your answer.
Thank you very much for your attention,
Lina Zapata
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Mail.
APAS Gait currently supports the following 5 marker
sets:
- Helen Hayes Original;
- Helen Hayes Modified;
- Vaughan Original;
- Vaughan Modified;
- Sun.
The desired marker set can be chosen in the 'general settings' tab
of the current gait analysis. You will find the recommended marker
locations for each marker set described in the APAS Gait documentation.
For Kistler platforms the following channel order is assumed
for calculating moments and torques: Fx12|Fx34|Fy14|Fy23|Fz1|Fz2|Fz3|Fz4.
I hope this answers your questions.
Best regards - Rudolf Buijs, Ariel Dynamics Inc.
----- Original Message -----
From: Tomi Vnttinen <tomi@KIHU.jyu.fi>
To: <info@arieldynamics.com>
Sent: Friday, February 25, 2000 4:33 AM
Subject: Still have a problem
> Hello again.
>
> I recently asked about marker setup for gait analysis when using only
> one kisttler force plate.
>
> So what is the presice marker setup for digitazing and does the
> channel order matter in the analog file if I wish to utilize the 3D
> kinetics module (I can`t figured out it from your web manuals).
>
> At this time replay would be nice.
>
> That`s all Folks
> Tomi
> tomi@kihu.jyu.fi
>
Hello Dr. Seong Jae Lee,
Thank you for your message. The
points required for each marker set are described in the APASGait
user manual. The direct address for the "on-line"
manual is listed below.
Please review the information and feel
free to contact us for any additional information.
Sincerely,
John Probe
Ariel Dynamics, Inc.
>
>
rmlee@anseo.dankook.ac.kr
> E-mail:
> Fax: +82-41-551-7062
> Phone: +82-41-550-3898
>
> Korea
> Choongnam 330-715
> San 16-5, Anseodong, Cheonan
> Dankook University Hospital
> Department of Rehabilitation Medicine
>
> Seong Jae Lee, M.D.
>
> Sincerely,
>
> Please let me know how to measure or calculate it.
> marker set.
> measure or calculate it. I'm supposed to use Helen Heyes
modified
> what "anterior-posterior ASIS/HJC component" means
and how to
> But among many items in anthropometric data, I just don't
understand
> It is working well and easy to use.
> I downloaded APASGAIT and have been trying it.
>
> Dear Dr. Ariel,
Subject: Question about the anthropometry in APASGAIT
Sent: Tuesday, March 06, 2001 7:15 PM
>
gideon@arielnet.com
To: "Gideon Ariel" <
>
rmlee@anseo.dankook.ac.kr
From: "Seong Jae Lee" <
----- Original Message -----