Foot Pressure Feedback Pneumatic Orthosis: Implication of Daily Life Walking Training for Knee Osteoarthritis Patients

Patients with knee osteoarthritis (KOA) usually experience pain in the medial compartment of their knee which accompany varus postures. This causes much larger lateral-side foot pressure than that of the medial side which may lead to functional limitation in their daily life. Reducing knee loading during gait could help patients with KOA alleviate pain and improve walking functions. In this study, a prototype for a new pneumatic knee orthosis (PKO) is developed to support the knee by increasing the pneumatic pressure of the PKO during the stance period of walking using foot pressure feedback in real time. Force-sensing resistor sensors in the PKO were used to detect the gait phase and monitor the foot pressures in real time. To investigate the feasibility of the system, walking tests on a treadmill were performed at 2 km/h and 3 km/h by healthy subjects. The results show that the developed PKO can reduce lateral-side foot pressure during stance phase. The PKO in this study could be used as a research tool to investigate the relationship between foot pressure and knee loading as well as therapeutic purposes to reduce medial compartment loading in the knee.