The Model of Center of Pressure Progression for Adults

This study aims to build the model of center of pressure progression (COPP) for adults. The COPP is a trajectory of center of foot pressure. The effect of walking speed and gender on COPP model will be elucidated in this study. Thirty health young adults (15 men and 15 women) were recruited to participate in this study. All subjects did not have relevant musculoskeletal disease and all of them have the normal arch curve (arch index/AI range between 0.21~0.26). A nested-factorial experimental design was applied. All subjects were asked to walk under four different speeds (self-selected, 3 km/hr, 4 km/hr and 5 km/hr) separately. A foot pressure measurement system (RS-scan ® system) was used to collect data of the center of pressure (COP) progression, progression angle (PA) and the velocity of COP. The results of this study indicate that the percentage of time (% time) of the stance phase in initial contact phase (ICP), forefoot contact phase (FFCP), foot flat phase (FFP) and forefoot push-off phase (FFPOP) were about 7.0%, 4.8%, 48.8% and 39.4%, respectively. The progression angle (PA) is 4.1degree (SD=1.6) with an inward curve and the average velocity of COP is 31.6 cm/s (SD=5.3) for the COPP model. Walking speed influences the % time of the stance phase in the FFP and FFPOP. As the increasing walking speed, the time % of COP progression diminishes on the FFP and increase on the FFPOP. Moreover, gender effect affect the progression angle, males have significantly larger deviating angle than males during the FFCP, FFP and FFPOP. The COPP model can be the useful information for clinical rehabilitation in evaluation, gait training, and footwear design.