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Dear Biomch-L's,
Thank you very much to all who responded to my question regarding
filming of rowing technique. The summary of the messages follows
after the original posting.
Marcin Jaszczak
************The original posting**************
Dear Sir,
I would like to film the rowing technique to study it.
There is a moment during rowing when the upper extremity cover the
knee.I cannot see the landmark on the knee this time.
Could you tell me what should I do to determine the displacement of
the landmark during rowing please.
Thank you very much.
Marcin Jaszczak
e-mail:jaszczak@sci.awf.wroc.pl
**************The summary*****************
You mention a single knee marker. If you are doing 2-D analysis you
can probably calculate the knee marker location from the ankle and
hip markers an the leg segment lengths.
Lawrence D. Abraham, EdD
Associate Dean
College of Education
SZB 216
The University of Texas at Austin
Austin, TX 78712
(512)471-3476
FAX: (512)475-8159
http://www.edb.utexas.edu/abraham
Larry Abraham
-------------------
1) Perhaps you can use two cameras and film the port and starboard
> views of the rowers. Then you could get both the left and the right knees
> on tape. The knees move approximately together and you could estimate the
> position of the hidden knee by viewing the unhidden knee on the opposite
> side.
>
> 2) You could use a non-optical method of tracking knee motion. The stroke
> seat has a magnet under it to measure the stroke rate. You could use
> a similar principle and tape magnets to the knee and have it induce
> current in sensors attached to the gunwhales of the boat. However the
> distance between the knees and the gunwhales are most likely prohibitively
> large.
>
> Good luck,
> Doug
Douglas Chang
-------------------
Why don't you place two markers on both thigh and shank segments away
> from the knee joint centre. This defines the line of the segment
> without the necessity for placing a marker on the knee. For 3D
> analysis you will require at least 3 markers per segment.
>
> Cheers,
>
> Jon.
>
>
>
>
> Jonathan Shemmell
>
> The Department of Human Movement Studies
> The University of Queensland
> Brisbane 4072
> Australia
>
> Ph +61 7 3365 6240
> Fax +61 7 3365 6877
> jshemm@hms.uq.edu.au
---------------
This is a problem we have experienced too. We place a marker on the shank
> two thirds of the way from the ankle to the knee. We measure this
> accurately and then recalculate the position of the knee after the record
> has been digitised.
>
> Good luck,
>
> Richard
Richard Smith e-mail: R.Smith@cchs.usyd.edu.au +
> + Research Manager, School of Exercise and Sport Science +
> + Faculty of Health Sciences, ,-_|\ +
> + The University of Sydney voice: +61 2 9351 9462 / \ +
> + East Street, Lidcombe, NSW 2141 fax: +61 2 9351 9204 \_,-._* +
> + AUSTRALIA v +
> + http://www.cchs.usyd.edu.au/Academic/ESS/smith/richard.html
-----------------
for sure you cannot make visible what is unvisible. But if you fix
> one marker plate with a local frame on the skin above the Trochanter
> maior and another one on the anterior face of the tibia, you should
> be able to extrapolate the location of the knee (axis) from the
> informations about the relative orientation of femur, knee and shank
> markers you get just before and after invisibility of markers.
>
> Hartmut
> __________________________________________________ _________
>
> Priv.-Doz. Dipl.-Ing. (mach.) Dr. med. (habil.) Hartmut Witte
> Facharzt fuer Anatomie
>
> http://SGILoco.zoo.uni-jena.de/~witte/
>
> DFG-Schwerpunktprogramm "Autonomes Laufen"
> Institut fuer Spezielle Zoologie und Evolutionsbiologie
> mit Phyletischem Museum
> Erbertstrasse 1
> D-07743 Jena
>
> Hartmut.F.Witte@gmx.de
>
> Fon ++49 3641 949 140/158 (university)
> ++49 3641 212 483 (D-07745 Jena, Ernst-Haeckel-Platz 1)
> ++49 2363 345 35 (D-45711 Datteln, Pestalozzistrasse 25)
> ++49 172 7951 255 (D2-mobile)
>
> Fax ++49 3641 949 142 (university)
> ++49 2363 35170 (on demand in Datteln)
------------------
Marcin, I read your email on biomech-l about filming of rowing. I have
> done some 2-D analysis of rowing in the past and hava found that the upper
> extremity does cover the knee during the recovery phase of the stroke (and
> any markers which you may be using to mark the knee). What we did instead
> was place markers at the hip, ankle, mid thigh and mid shank. The
> mid-segment markers were placed along the long axes of the femur and tibia
> so that when the lines were extended from the two limb "segments" they
> would cross at the knee joint. Many motion analysis packages will then be
> able to track this "virtual point" without actually having a physical
> marker at the knee. You can then compute angles and displacements. For
> 3-D analysis, the marher placement would ba a bit more complex and you
> would have to work it out. I hope this helps. E-mail me if you have any
> questions.
>
> Scott Riewald
>
> Scott Riewald
> Northwestern University
> (312) 908-4766
> e-mail: sriewald@nwu.edu
-----------------
You can look my paper in ISBS'96, i explain it.
Yours sincerely.
Philippe Pudlo
----------------
I decided to answer as if you meant the question to go
> to everyone on the list. For your filming of rowing, if you have
> at least two markers along the upper and lower segments of the
> legs which remain visible at all times you can probably
> extend lines toward the knee and place the knee at the point
> of intersection of these lines.
>
> Good luck with your research. I have rowed for 11 years now and
> I appreciate hearing about research being done on the sport.
>
> Mary Hannan
mkh@obl.bidmc.harvard.edu (Mary K. Hannan)
-------------------
Hello, my name is Ivan Hooper and I am one of the physiotherapists for =
> the Australian Rowing Team. I have done some research on angular and =
> linear displacements during rowing on an ergometer over the last few =
> years. It was part of Bachelor of Science (Human Movement Studies) and =
> Master of Sports Physiotherapy degrees that I did at the University of =
> Queensland. Are you using reflective markers and 2D motion analysis for =
> determination of joint angles? If so, here is an explanation that is =
> part of a directed study I did two years ago.=20
> "The kinematic data was obtained by placing ten spherical markers (30mm =
> diameter) on the subject and ergometer in the following locations: =
> spinous process of the first thoracic vertebra (T1); left anterior =
> superior iliac spine (ASIS); left posterior superior iliac spine (PSIS); =
> superior point of the left greater trochanter (GT); the lateral surface =
> of the left thigh on a line joining the greater trochanter to the centre =
> of the knee joint (FEMUR); left lateral malleolus; the lateral surface =
> of the left shank on a line joining the lateral malleolus with the knee =
> joint centre; left fifth metatarsal; dorsal surface of the left hand and =
> the cage of the ergometer. These markers were used to define lumbar =
> vertebral, hip, knee and ankle angles, as well as the forward reach =
> distance at the catch.
>
>
> The use of markers on T1, PSIS, ASIS, GT, and FEMUR to separate pelvic =
> and lumbar vertebral movement has been radiographically verified =
> (Kippers and Parker, 1989) and used in subsequent studies =
> (Burgess-Limerick et al, 1993, 1995). All angles were defined as =
> included angles which decrease during flexion. Hip angle was defined as =
> the anterior angle subtended between the line joining PSIS and ASIS and =
> the extrapolated line of the femur (as defined by FEMUR and GT =
> markers)."
>
> Currently I am continuing research on lower back injuires in rowers and =
> using this system to analyse the joints described above. I hope this =
> makes sense and is of use. Let me know how you go.
>
> Regards
>
> Ivan Hooper
>
> Ivan Hooper=20
> Optima Physiotherapy & Massage Therapy
> Cnr Ashgrove Ave & Enoggera Rd
> Newmarket Q 4051
> (W) 07 3356 3312 (F) 07 3356 0234
> (H) 07 3371 7881 (M) 0413 946 308
> EMail : ivanhooper@ozemail.com.au
-----------------
I was sent a copy for your e-Mail from Trevor Coen. I may be able to help
> you but I need more information on what you are trying to study and what
> system you are using to do your analyising. You can e-Mail me or phone me
> on 00 353 61 202895.
> I would love to hear about you research
>
> Feargal O'Callaghan
> feargal.o'callaghan@ul.ie
---------------
Check at http://www.arielnet.com
--------------
I propose to place additional four markers on the upper and lower
leg. =
> By using this markers you define two lines that intersect in the knee =
> joint. When the knee marker becomes visible again, you use it.
>
> Kind regards
>
> J=F6rg Eggers,
> Qualisys GmbH
>
> Qualisys GmbH
> Filiale Hamburg
> Bahnhofstra=DFe 112
> D-22844 Norderstedt
> Tel.: +49 40 526 828 44
> Fax: +49 40 526 828 45
> Mobil: +49 171 30 30 997
> Email: j.eggers@mail.hh.provi.de
> Web: http://www.qualisys.se
----------------
For getting the knee landmark without any problem no matter their
technique, you should place marker at:
1. ankle
2. middle shank
3. knee
4, middle thigh
5. hip
You are able to get the knee angle with the elongation of the
segments determined by the points 1/2 and 4/5.
Good luck. Write me back if you need further information.
CLARICE TANAKA, PhD
Biomechanics Laboratory
School of Physical and Occupational Therapy
McGILL UNIVERSITY
3630 Drummond Street
phone (514) 398-5599
fax (514) 398-8193
Montreal, Quebec, Canada
H3G 1Y5
-------------------------------------------------------------------
To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://www.bme.ccf.org/isb/biomch-l
-------------------------------------------------------------------
Thank you very much to all who responded to my question regarding
filming of rowing technique. The summary of the messages follows
after the original posting.
Marcin Jaszczak
************The original posting**************
Dear Sir,
I would like to film the rowing technique to study it.
There is a moment during rowing when the upper extremity cover the
knee.I cannot see the landmark on the knee this time.
Could you tell me what should I do to determine the displacement of
the landmark during rowing please.
Thank you very much.
Marcin Jaszczak
e-mail:jaszczak@sci.awf.wroc.pl
**************The summary*****************
You mention a single knee marker. If you are doing 2-D analysis you
can probably calculate the knee marker location from the ankle and
hip markers an the leg segment lengths.
Lawrence D. Abraham, EdD
Associate Dean
College of Education
SZB 216
The University of Texas at Austin
Austin, TX 78712
(512)471-3476
FAX: (512)475-8159
http://www.edb.utexas.edu/abraham
Larry Abraham
-------------------
1) Perhaps you can use two cameras and film the port and starboard
> views of the rowers. Then you could get both the left and the right knees
> on tape. The knees move approximately together and you could estimate the
> position of the hidden knee by viewing the unhidden knee on the opposite
> side.
>
> 2) You could use a non-optical method of tracking knee motion. The stroke
> seat has a magnet under it to measure the stroke rate. You could use
> a similar principle and tape magnets to the knee and have it induce
> current in sensors attached to the gunwhales of the boat. However the
> distance between the knees and the gunwhales are most likely prohibitively
> large.
>
> Good luck,
> Doug
Douglas Chang
-------------------
Why don't you place two markers on both thigh and shank segments away
> from the knee joint centre. This defines the line of the segment
> without the necessity for placing a marker on the knee. For 3D
> analysis you will require at least 3 markers per segment.
>
> Cheers,
>
> Jon.
>
>
>
>
> Jonathan Shemmell
>
> The Department of Human Movement Studies
> The University of Queensland
> Brisbane 4072
> Australia
>
> Ph +61 7 3365 6240
> Fax +61 7 3365 6877
> jshemm@hms.uq.edu.au
---------------
This is a problem we have experienced too. We place a marker on the shank
> two thirds of the way from the ankle to the knee. We measure this
> accurately and then recalculate the position of the knee after the record
> has been digitised.
>
> Good luck,
>
> Richard
Richard Smith e-mail: R.Smith@cchs.usyd.edu.au +
> + Research Manager, School of Exercise and Sport Science +
> + Faculty of Health Sciences, ,-_|\ +
> + The University of Sydney voice: +61 2 9351 9462 / \ +
> + East Street, Lidcombe, NSW 2141 fax: +61 2 9351 9204 \_,-._* +
> + AUSTRALIA v +
> + http://www.cchs.usyd.edu.au/Academic/ESS/smith/richard.html
-----------------
for sure you cannot make visible what is unvisible. But if you fix
> one marker plate with a local frame on the skin above the Trochanter
> maior and another one on the anterior face of the tibia, you should
> be able to extrapolate the location of the knee (axis) from the
> informations about the relative orientation of femur, knee and shank
> markers you get just before and after invisibility of markers.
>
> Hartmut
> __________________________________________________ _________
>
> Priv.-Doz. Dipl.-Ing. (mach.) Dr. med. (habil.) Hartmut Witte
> Facharzt fuer Anatomie
>
> http://SGILoco.zoo.uni-jena.de/~witte/
>
> DFG-Schwerpunktprogramm "Autonomes Laufen"
> Institut fuer Spezielle Zoologie und Evolutionsbiologie
> mit Phyletischem Museum
> Erbertstrasse 1
> D-07743 Jena
>
> Hartmut.F.Witte@gmx.de
>
> Fon ++49 3641 949 140/158 (university)
> ++49 3641 212 483 (D-07745 Jena, Ernst-Haeckel-Platz 1)
> ++49 2363 345 35 (D-45711 Datteln, Pestalozzistrasse 25)
> ++49 172 7951 255 (D2-mobile)
>
> Fax ++49 3641 949 142 (university)
> ++49 2363 35170 (on demand in Datteln)
------------------
Marcin, I read your email on biomech-l about filming of rowing. I have
> done some 2-D analysis of rowing in the past and hava found that the upper
> extremity does cover the knee during the recovery phase of the stroke (and
> any markers which you may be using to mark the knee). What we did instead
> was place markers at the hip, ankle, mid thigh and mid shank. The
> mid-segment markers were placed along the long axes of the femur and tibia
> so that when the lines were extended from the two limb "segments" they
> would cross at the knee joint. Many motion analysis packages will then be
> able to track this "virtual point" without actually having a physical
> marker at the knee. You can then compute angles and displacements. For
> 3-D analysis, the marher placement would ba a bit more complex and you
> would have to work it out. I hope this helps. E-mail me if you have any
> questions.
>
> Scott Riewald
>
> Scott Riewald
> Northwestern University
> (312) 908-4766
> e-mail: sriewald@nwu.edu
-----------------
You can look my paper in ISBS'96, i explain it.
Yours sincerely.
Philippe Pudlo
----------------
I decided to answer as if you meant the question to go
> to everyone on the list. For your filming of rowing, if you have
> at least two markers along the upper and lower segments of the
> legs which remain visible at all times you can probably
> extend lines toward the knee and place the knee at the point
> of intersection of these lines.
>
> Good luck with your research. I have rowed for 11 years now and
> I appreciate hearing about research being done on the sport.
>
> Mary Hannan
mkh@obl.bidmc.harvard.edu (Mary K. Hannan)
-------------------
Hello, my name is Ivan Hooper and I am one of the physiotherapists for =
> the Australian Rowing Team. I have done some research on angular and =
> linear displacements during rowing on an ergometer over the last few =
> years. It was part of Bachelor of Science (Human Movement Studies) and =
> Master of Sports Physiotherapy degrees that I did at the University of =
> Queensland. Are you using reflective markers and 2D motion analysis for =
> determination of joint angles? If so, here is an explanation that is =
> part of a directed study I did two years ago.=20
> "The kinematic data was obtained by placing ten spherical markers (30mm =
> diameter) on the subject and ergometer in the following locations: =
> spinous process of the first thoracic vertebra (T1); left anterior =
> superior iliac spine (ASIS); left posterior superior iliac spine (PSIS); =
> superior point of the left greater trochanter (GT); the lateral surface =
> of the left thigh on a line joining the greater trochanter to the centre =
> of the knee joint (FEMUR); left lateral malleolus; the lateral surface =
> of the left shank on a line joining the lateral malleolus with the knee =
> joint centre; left fifth metatarsal; dorsal surface of the left hand and =
> the cage of the ergometer. These markers were used to define lumbar =
> vertebral, hip, knee and ankle angles, as well as the forward reach =
> distance at the catch.
>
>
> The use of markers on T1, PSIS, ASIS, GT, and FEMUR to separate pelvic =
> and lumbar vertebral movement has been radiographically verified =
> (Kippers and Parker, 1989) and used in subsequent studies =
> (Burgess-Limerick et al, 1993, 1995). All angles were defined as =
> included angles which decrease during flexion. Hip angle was defined as =
> the anterior angle subtended between the line joining PSIS and ASIS and =
> the extrapolated line of the femur (as defined by FEMUR and GT =
> markers)."
>
> Currently I am continuing research on lower back injuires in rowers and =
> using this system to analyse the joints described above. I hope this =
> makes sense and is of use. Let me know how you go.
>
> Regards
>
> Ivan Hooper
>
> Ivan Hooper=20
> Optima Physiotherapy & Massage Therapy
> Cnr Ashgrove Ave & Enoggera Rd
> Newmarket Q 4051
> (W) 07 3356 3312 (F) 07 3356 0234
> (H) 07 3371 7881 (M) 0413 946 308
> EMail : ivanhooper@ozemail.com.au
-----------------
I was sent a copy for your e-Mail from Trevor Coen. I may be able to help
> you but I need more information on what you are trying to study and what
> system you are using to do your analyising. You can e-Mail me or phone me
> on 00 353 61 202895.
> I would love to hear about you research
>
> Feargal O'Callaghan
> feargal.o'callaghan@ul.ie
---------------
Check at http://www.arielnet.com
--------------
I propose to place additional four markers on the upper and lower
leg. =
> By using this markers you define two lines that intersect in the knee =
> joint. When the knee marker becomes visible again, you use it.
>
> Kind regards
>
> J=F6rg Eggers,
> Qualisys GmbH
>
> Qualisys GmbH
> Filiale Hamburg
> Bahnhofstra=DFe 112
> D-22844 Norderstedt
> Tel.: +49 40 526 828 44
> Fax: +49 40 526 828 45
> Mobil: +49 171 30 30 997
> Email: j.eggers@mail.hh.provi.de
> Web: http://www.qualisys.se
----------------
For getting the knee landmark without any problem no matter their
technique, you should place marker at:
1. ankle
2. middle shank
3. knee
4, middle thigh
5. hip
You are able to get the knee angle with the elongation of the
segments determined by the points 1/2 and 4/5.
Good luck. Write me back if you need further information.
CLARICE TANAKA, PhD
Biomechanics Laboratory
School of Physical and Occupational Therapy
McGILL UNIVERSITY
3630 Drummond Street
phone (514) 398-5599
fax (514) 398-8193
Montreal, Quebec, Canada
H3G 1Y5
-------------------------------------------------------------------
To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://www.bme.ccf.org/isb/biomch-l
-------------------------------------------------------------------