Simple Force Plate for Undergraduate Courses

[Stefan Litzenberger]

Dear community.
I recently stepped across some very affordable "Force Plates". We thought we could use those for different simple lab exercises in our undergraduate courses.

one-dimensional (vertical)

http://www.conatex.com/shop/product_info.php?cPath=1_44_125&products_id=134

two-dimensional (vertical, horizontal)

http://www.conatex.com/shop/product_info.php?cPath=1_44_125&products_id=138

Does anyone have any experience with those? Do they give at least an agreeable result?

size is a little small for Gait Analysis (35x35cm) but could work for e.g. jumps (range: -1,1 kN to +4,4 kN, +/-1,1kN horizontal)

Thanks for your replies
Regards
Stefan

[Gannon White]

Re: Simple Force Plate for Undergraduate Courses

I purchased 2 of the 2 axis FPs for "cost effectiveness" reasons for my undergrad labs. They work fine with sampling rates from 10-1000 Hz. The software is pretty easy to learn and manipulate...even the students can run the software easily. Getting data off and into excel is done ONE data array at a time So if I want V & AP forces during a CM jump from each foot I have 4 txt files to download. Other than that I think they are fine!

[Stefan Litzenberger]

Re: Simple Force Plate for Undergraduate Courses

Gannon,
Thanks for the helpful reply. Sounds just like the thing we are looking for.
Just one more question. How are data transferred? USB? or is it possible to get access to the analogue data too?
Regards from Vienna
Stefan

[Gannon White]

Re: Simple Force Plate for Undergraduate Courses

Two ways.

http://www.pasco.com/prodCatalog/PS/...-glx/index.cfm This is a stand alone collection unit good for going places without a computer. I believe then you upload data to the computer (I've never used it). This can take 4 items at once.

http://www.pasco.com/prodCatalog/PS/...link/index.cfm GET THIS USB link. As soon as you plug in the unit (FP or other item) the software launches and recognizes the equipment. You can collect data from as many items as you have USB ports. Then collect data and either export a txt file to be imported into excel or copy and paste from the software's "table" display of data. As I stated, there is no way to export more than 1 array (i.e., FP direction, accelerometer direction) of data plus the time array at once. But for student projects it works great.

Both FPs are cost effective but I suggest the 2-axis version. Let me know how they turn out if you go with them.

[Stefan Litzenberger]

Re: Simple Force Plate for Undergraduate Courses

Thanks for the additonal information!
Sounds great.
Regards
Stefan

[Christopher Proulx]

Re: Simple Force Plate for Undergraduate Courses

I completely agree with Gannon. They certainly are a viable option and for the cost, simplicity, and ability to collect with several of the collection options, it really allows students to be creative. We also use have used the airlink for the accelerometers to become wireless. There are smaller options out there, but again returning to cost consideration you could feasibly set up several lab stations with a simple to use software, that also allows for some further calculations.

Yes, they are a little small, so we built a platform to have FPs side by side (and provide for safer landing and larger surface area) for vertical jump, landing, GRF, RFD, etc during weight lifting and jumping. Because they are so light and moveable, comparably, we've put them on the walls as well; students were comparing RFP in UE/torso pushing motions.

Best, Chris

[Stefan Litzenberger]

Re: Simple Force Plate for Undergraduate Courses

Dear all!
Finally we have managed to purchase one of the 2-axis plates and a group of students has tried to evaluate the Pasco data versus an AMTI OR 6-7 (by simply placing the Pasco onto the AMTI and performing normal gait and a counter movement jump). The results were rather good for the vertical forces, but medio-lateral forces showed big deviations. (I have two graphs - taken from the students' laboratory paper - attached which illustrate the results .)
Furthermore we noticed that the upper cover of the plate moves horizontally in respect to the base of the force plate. This seems to cause the spikes you can see in the diagrams of the medio-lateral ('parallel') forces (i.e. when the movement of the upper plate is suddenly coming to a dead stop.)
Has anyone made the same experience?
However as a conclusion it can be stated that the plates offer a great option for courses to obtain first experience with GRF data.
Best regards from Vienna
Stefan

Edit: As the pngs were thumbnailed I have attached zip-files with the plots