Optimal positions for foot pressure sensors in walking analysis

We suggest the optimal position of sensors used for measuring foot pressure. Foot pressures were obtained from 11 healthy persons (6 men and 5 women) while they were walking on a treadmill for 1 minute at 3 km/h. The order of high correlation coefficients were in: the heel region (r = -0.35 on sensor number 10), the metatarsal region (r = -0.27 on sensor number 79), the toe region (r = -0.19 on sensor number 74) and the barefoot region (r = -0.10 on sensor number 68), respectively. However, the pressure could not show angle information of the foot, even though this is also important for gait diagnosis or daily monitoring. Therefore, we analyzed the foot angle using a 9DOF (6-degree of freedom) IMU sensor. From the results, the highest negative pitch angle occurred at the moment of heel strike, while the highest positive pitch angle occurred at the moment of toe roll-off. Thus, both of the foot pressure and the angle information could increase the accuracy and usfulness of walking or gait analysis.