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mvanoncini99
09-07-2011, 10:51 AM
Dear subscribers,
I am doing a bit of marketing research on systems to measure knee and ankle angles for proprioception testing.

So far we have been conducting tests on the with a subject sitting on a chair with 2 rotating platforms to hold the feet.
The subject is asked to sit on the chair, and to reproduce (passively or actively) a certain angle of dorsiflexion.
The angle of dorsiflexion is measured with a system based on accelerometers (unknown precision); one unit is attached to the foot, one unit is attached to the shank.
The feet are strapped to the platforms,
which rotate on an axis which is in the same position, with respect to the chair, for all the subjects (i.e. not the ankle axis...).


We would like to conduct further testing in a sport centre, and hence we're looking for a better solution...
Our dream system would be:

-easy to operate for non technical staff (easy don...based on straps, even an electrogoniometer will be considered too difficult to use...);
-allowing to measure both knee flexion/extension and ankle dorsi/plantar flexion
-providing some sort of electronic output (analogue, digital,saving on a memory card...) the final goal being to import data on a pc
-very low budget

I wonder if Biomech-L readers have any experience with devices which are already on the market?
Any other ideas on devices developed for research purposes will also be welcomed!
I have in mind a solution based on a brace/orthosis, but maybe it is worth looking into non-commercial markerless mocap systems?

Thank you for your help...

Best regards,
Michele Vanoncini

sibasina
09-08-2011, 04:17 AM
Dear Vanoncini

You may capture the flexion/extension of the joint in saggital plane using video cameras, then analyze it with a free video analysis software which is available on the internet. you can google it.

Best
Sina

jwilliams33
09-09-2011, 02:33 AM
Michele
A very simple system (and cheap) would use the Duo sensor product from ThetaMetrix.co.uk. This is specifically designed to be simple enough for admin staff to be able to use. It can easily collect the angles you are after and contrary to a 'brace' product can be attached in just a few seconds. I think you will find it meets all your requirements for cost and simplicity.
Regards

sabbott74
09-09-2011, 03:46 AM
Hello,

My work looks at knee joint angular velocity, and for that I have found the electrogoniometers produced by Biometrics Ltd more than adequate, don't know if they are necessarily that cheap though, depends on your budget, the sensors are about 500 ish, but you need the data logger as well, so you wouldn't get much change from 2-3000.... there may be cheaper solutions on the market though. Advantage is full portability, (my work has seen them used used happily on horses in stables!) They also have a "wireless" solution which removes the wire between datalogger and sensor pack, allowing me to have people or horses movng about.

Hope that helps

Steve Abbott