Abstract
A measurement of the force bearing down on the foot skeletal system through the foot sole is effective for the diagnosis of various foot disorders or the evaluation of the treatment. From this point of view a portable computerized gait analysis system has been developed here to record and analyze the dynamic under-foot force distribution in more daily-life-like situations. In this study some normal subject's dynamic under-foot force distribution in various modes of walking has been studied as the first step towards clinical application of this system.
This system is a kind of small battery-driven computer system (15×9×3cm, 700g) and is constructed of the minimum number of elements. It comprises the CPU (Z80), memory (64Kbyte), A/D converter, etc., necessary to measure various kinds of biological signal. The force distribution sensor used here is an ultra-thin pressure-strain guage (1.5mm in thickness and 8mm in diameter); eight sensors are fixed by adhesive tape on eight points on the foot sole, including the heel, the outside of the midfoot, five metatarsal heads and the great toe.
In the experiment the force distribution under the foot is measured in various modes of walking, that is, a voluntary speed walking, jogging, going up or down the stairs, etc. Results show that the force distribution diversely changes in each subject or mode of walking, but some new findings about the foot function could be acquired from these results. Moreover a method by using this system to analogize the force bearing down on the foot in daily life is proposed here.
