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rsahni25
06-29-2010, 04:42 AM
Dear BIOMCH-L members,

I would like remind that a few years back Tam Nguyen had also posted responses to
BIOMCH-L related to similar matter,, resembling to Miss Jenny Kent recent
responses. to subject line


Re: [BIOMCH-L] Help: 3DGA ankle marker placement for prosthetic feetTuesday,
February 12, 2008 3:15 PM
From: "Rabinder Sahni" Add sender to ContactsTo: "Tam
Nguyen"

Dear Tam

I do not consider 3DGA ankle marker to be a crucial factor.
I view complete prosthetic foot as an inverted offset "T" into consideration.
Hence an adjustable pyramid (ankle) location may ease the alignment process.


The below mentioned points should be considered in selecting a prosthetic foot
1) Location of pyramid (ankle) with respect to length of foot.
2) Length of foot with reference to sound foot in case of unilateral BK amputees.
3) Stiffness of fore foot as well heel damper.

Answers to your question mentioned below.

1) ( NOT CRITICAL)

2) ( ADJUSTABLE PYRAMID ANKLE TOWARDS FORE OR REAR FOOT
ADVISED)

3) (CERTAINLY RIGHT WITHOUT IGNORING OTHER POINTS)


Thanks

Mr.Rabinder Sahni
Prosthetics R&D, Designer lower limbs, Self user
INDIA
Tam Nguyen wrote:
Dear all,
We are about to begin a study looking at the functional performance between
three prosthetic feet (SACH, dynamic and multi-axial)using 3D gait analysis
in our VICON equipped laboratory. We found the following articles with
description of the ankle marker placement as on the spot corresponding to
the lateral malleolus on the unaffected side.
* Sjodahl et al. Kinematic and kinetic gait analysis in the sagittal plane
of trans-femoral amputees before and after special gait re-education.
Prosthet Orthot Int 2002; 26: 101-112
* Bateni and Olney. Effect of weight of prosthetic components on the gait of
tran-tibial amputees. JPO 2004; 16(4):113-120

We also found a few similar articles but the authors did not specify the
location of the ankle maker placement. We want to make sure that maker
placements are appropriately placed to represent the function of the feet
design and to avoid potential errors in the kinematics and kinetics
measurements. So our questions are:

1. Is there a standard maker placement for prosthetic feet study?
2. What would be the reasons for choosing the same spot to the lateral
malleolus on the unaffected side?
3. Would it be more accurate to place the maker where the approximate ankle
joint centre/ axis of rotation is located? (As these locations are
definitely different within the three feet designs and certainly are
different from the unaffected side)
Look forward to your responses and will post a summary.
Regards,

Tam Nguyen
Manager, South Australian Movement Analysis Centre
Department of Rehabilitation & Aged Care
Repatriation General Hospital
Daws Rd, DAW PARK, SA 5041
Australia
e: tam.nguyen@rgh.sa.gov.au
t: +61 8 8275 2848
f: +61 8 8275 1130
---------------------------------------------------------------
Information about BIOMCH-L: http://www.Biomch-L.org
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Re: [BIOMCH-L] Help: 3DGA ankle marker placement for prosthetic feetTuesday,
February 12, 2008 3:15 PM
From: "Rabinder Sahni" Add sender to ContactsTo: "Tam
Nguyen"

Dear Tam

I do not consider 3DGA ankle marker to be a crucial factor.
I view complete prosthetic foot as an inverted offset "T" into consideration.
Hence an adjustable pyramid (ankle) location may ease the alignment process.


The below mentioned points should be considered in selecting a prosthetic foot
1) Location of pyramid (ankle) with respect to length of foot.
2) Length of foot with reference to sound foot in case of unilateral BK amputees.
3) Stiffness of fore foot as well heel damper.

Answers to your question mentioned below.

1) ( NOT CRITICAL)

2) ( ADJUSTABLE PYRAMID ANKLE TOWARDS FORE OR REAR FOOT
ADVISED)

3) (CERTAINLY RIGHT WITHOUT IGNORING OTHER POINTS)


Thanks

Mr.Rabinder Sahni
Prosthetics R&D, Designer lower limbs, Self user
INDIA
Tam Nguyen wrote:
Dear all,
We are about to begin a study looking at the functional performance between
three prosthetic feet (SACH, dynamic and multi-axial)using 3D gait analysis
in our VICON equipped laboratory. We found the following articles with
description of the ankle marker placement as on the spot corresponding to
the lateral malleolus on the unaffected side.
* Sjodahl et al. Kinematic and kinetic gait analysis in the sagittal plane
of trans-femoral amputees before and after special gait re-education.
Prosthet Orthot Int 2002; 26: 101-112
* Bateni and Olney. Effect of weight of prosthetic components on the gait of
tran-tibial amputees. JPO 2004; 16(4):113-120

We also found a few similar articles but the authors did not specify the
location of the ankle maker placement. We want to make sure that maker
placements are appropriately placed to represent the function of the feet
design and to avoid potential errors in the kinematics and kinetics
measurements. So our questions are:

1. Is there a standard maker placement for prosthetic feet study?
2. What would be the reasons for choosing the same spot to the lateral
malleolus on the unaffected side?
3. Would it be more accurate to place the maker where the approximate ankle
joint centre/ axis of rotation is located? (As these locations are
definitely different within the three feet designs and certainly are
different from the unaffected side)
Look forward to your responses and will post a summary.
Regards,

Tam Nguyen
Manager, South Australian Movement Analysis Centre
Department of Rehabilitation & Aged Care
Repatriation General Hospital
Daws Rd, DAW PARK, SA 5041
Australia
e: tam.nguyen@rgh.sa.gov.au
t: +61 8 8275 2848
f: +61 8 8275 1130

Information about BIOMCH-L: http://www.Biomch-L.org
Archives: http://listserv.surfnet.nl/archives/Biomch-L.html