View Full Version : GRF normalization

Dalia Mosaad
06-23-2008, 09:20 PM
Colleagues, I'm conducting my doctoral thesis which requires measuring the 3-D ground reaction force (GRF) (vertical-antro posterior and mediolateral forces) in children.-I take the GRF for the children with different bag style -The child walk on a 5-meter walkway with the forceplate(AMTI) at the midway(i have only one force plate). - Firstly, the child walk without bag as a refernce value. - Then, the child carry one of the 2 bags ,each bag has 15%of the body weight, and walk along the walkway at a self selected velocity, repeating this step till making right foot landing mid-plate (3-5 trials). In my data collection, i should normalize my kinetic data :
-when the subject walk without bag, force data are normalized as a percentage as in this formula (100X N force/N body weight)

- But i'm not sure when i make percentage in case of subject carries bag with weights :
if it is right to divide the force over N body weight or divide on (body weight+bag weight)

wait for your help
Thanks in advance for your insights. Dalia Mosaad, PT, PhD studentAssisstant lecturer Faculty of physical therapyCairo University daliamosaad@hotmail.com
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