simtk.org

Hi, just wondering if the gaitextracttoolbox is suitable for non-gait situations such as rising from a seated position as described in my previous posting?

Thanks

Hi Samuel,

The gaitextracttoolbox is a separate project, I'd suggest you contact the admin on it to find out what it supports. By the way, do you have an instrumented seat or handles?

Good luck,
-Ayman

Hi Ayman,

Thanks for the reply,

The data I have is only pilot data, collected so that I could iron out any bugs and try and calculate joint reaction forces primarily for the lumbar region of the spine. We just used a basic office chair, nothing fancy, which was placed alongside a single force plate with both of the subjects feet on the plate. I've had a look at the instruction manual for the toolbox and as the name suggests I believe that it is designed primarily for gait. Was just after an easy way to develop .mot files for the ground reaction forces. I'll contact admin as you suggested to clarify.

Regards

Sam

Hi Samuel,

The toolbox is very easy to modify for sit-to-stand or squat tasks. I was able to do that in MATLAB.

Snehal

Hi Snehal,

Just wondering if you used a single force plate or one plate for each foot (assuming a two leg squat)? I've only used a single force plate but because of the symmetrical natural of the problem was hoping to split the grf's evenly between each leg.

Hi Samuel,

I just saw something I am pretty interested from your saying about what you are doing about to split the GRF's evenly.

Now I am doing sort of reverse process, that I am trying to combine the data from two single force plate and combine them together to form a whole gait cycle. Any thoughts about whether you think this is realistic or not?

Thanks for any reply.

Yi Wang
University of Utah

Hi Samuel,

Just understand what you are talking about the one force plate, so you only use one force plate for your subject to stand one? Our lab got this situation for one of the project too, my friend using two force plates for two knees and two toes to knee down on them. Which he has to extract data from one force plate to get two vector force, one from knee part and other from toe, is that the situation similar to yours?

Yi Wang
University of Utah

Hi Samuel,

I used two separate force plates.
As far as I can tell from my data, the individual forces for each leg can be very different. Splitting them evenly is contentious.

Snehal

Hi Yi,

I think my situation is quite different. The subject is standing with both feet on a single force plate and moves from a sitting position to a standing position and vice versa. From what others have said two force plates would be more appropriate. I'm quite new to OpenSim, only been using it for about 6 weeks so just need to work through a few issues. Thanks for your responses and good luck with your research,

Sam

Hi,

Just wondering if a single force plate is used for one leg, can this force file (i.e.9 column vx,vy,vz,px,py,pz,torque x,y and z) be input into OpenSim or do you need to "cut up" the force data so it resembles the use of two force plates (i.e 18 columns)?