Sensorial structure for unobtrusive measurement of feet reaction force

Jogging is a good and popular exercise for human; however, inappropriate jogging habits may result in chronic sports injuries. This paper proposes an unobtrusive measurement of feet reaction forces for treadmill users during their exercise period. Knowing the feet reaction forces on-the-fly helps users to prevent chronic movement injury due to inappropriate jogging gaits. The proposed feet reaction force sensorial structure is composed of load cell sensors, signal amplifying circuits, and low-pass filtering circuits. The voltaic signals sensed by the load cells are transmitted to an 8052-based microprocessor for calculating the corresponding force values. Moreover, the proposed work demonstrates its potential injury awareness by monitoring reaction forces versus speeds for users. The experimental results show that this work is a precise, reliable, and economic reaction force measuring scheme for treadmill users. The measuring accuracy in static tests is within 1%.