Investigation of ground reaction force distribution beneath the foot in postural control

Akbarifar, Roshanak
It has been reported that the ground reaction force (GRF) beneath the foot is distributed by the ratio of 1/3 in metatarsals and 2/3 in calcaneous. The main aim of this thesis is to check the ratio of GRF distribution with respect to front and hint regions of the foot and to understand the importance of the distribution ratio/rule in postural control. A mathematical model is designed and simulated using MATLAB® and Simulink® in which the foot is modeled as a deformable body, instead of being rigid, which has widely been used as a modeling attempt in the previous literature. The output signals of model and their behaviors in time were compared with the next stage experimental results for any similarities. The second stage of the thesis is data collection. Data were collected using a pressure mat, a forceplate and a motion capture system. Data analyses were performed using codes written in MATLAB® and results were interpreted in different sections. Results showed that subjects were standing more stable during bipedal trials rather than unipedal trials; and more stable during open-eyes trials rather than closed eyes. The “1/3 & 2/3” rule was observed in all of the trials but there were greater errors in unipedal trials than in bipedal because the stability of subjects was disturbed more frequently. Calculating the correlation between body center of pressure and different pressure components beneath foot, it was observed that center of pressure was mostly correlated with the pressure component under metatarsals of the right foot.
Citation Formats
R. Akbarifar, “Investigation of ground reaction force distribution beneath the foot in postural control,” M.S. - Master of Science, Middle East Technical University, 2014.