Force plate layout?

[Syed Wasim Raza]

Hi everyone,

I have started a gait lab with 3 force plates. The force plates are arranged in line with each other and separated from each other by 4 inch distances. I am facing a problem that most of the subjects miss the force plates or they hit the edges of the plates. Could someone advise me how much distance is recommended for separating the force plates or is there is a specific consensus on the arrangement of the force plate?

Regards
Wasim

[Edmund Cramp]

Re: Force plate layout?

I think that there are as many theories on the "correct" distance between force plates as there are labs - what you describe seems to be fine.

The trick is to start the subject at the right spot so that their foot strike has the best chance of hitting the plates and the way to do this is to place several "starting lines" at each end of the walkway ... you can use different colored tape across the walkway to indicate the starting lines - separate the lines by about 6 inches (150mm). You'll need four to five, or more, different starting lines depending on your subject population. The way that this works is that you start the subject on the middle starting line and watch them walk - watch which feet strike which plates and adjust their starting line forward or back depending on where their feet strike the plates until they hit all (or most) of the plates cleanly.

While it's nice to get a set of one, two, three, clean foot strikes, it's not going to happen all the time, or even most of the time. The main reason for having multiple plates in a gait lab is to maximize the chance of one clean strike on any given trial.

[Syed Wasim Raza]

Re: Force plate layout?

Dear Edmund Cramp,

I am very happy to see a reply from you, because today I read your comments and suggestions on clinical gait analysis page. Actually I used the same technique for collecting gait data of hip surgery patients for my PhD at gait lab at University of Dundee, UK. This worked well for the patients and I hope this will also work well at gait lab at my own home country. My university gait lab is the first lab in my country.

I am very thankful for your reply.

Regards

Dr.Syed Wasim Raza