Turning gait is very common in daily lives. However, study of turning is still limited. For researching the differences of the walking characteristics between straight gait and turning gait and between different turning strategies, and for analyzing the endopathic factor, this study selected 10 healthy young men to perform straight walking and 90° turning using two turning strategies (outside leg turning and inside leg turning). The Vicon capture system and plantar pressure capture system were used to measure gait parameters and plantar pressure parameters at the same time. The study showed that stride velocity reduced while stride time and proportion of stance time increased when turning was compared to straight walking. Inside leg turning strategy needed stronger muscle controlling and could promote turning, while outside leg turning strategy was more stable. This results will offer data for projecting gait of biped robot and provide reference value for walking rehabilitation training design and development of walking assistive equipments, etc.
Utilized coefficient of friction (UCOF), which is calculated with ground reaction forces (GRF), is an effective factor to predict the possibility of slip. For researching the UCOF values of different turning strategies and then predicting the possibility of slip, this study selected 10 healthy young men to perform straight walking and 60° and 90° turning using two turning strategies (step turning and spin turning). ATMI force plate was used to collect the data of GRF, and then the UCOF values of different walking conditions were calculated. The study showed that difference of the medial-lateral force in different walking conditions was great; the slip possibility of turning was significantly greater than that of straight walking. For spin turn, turning angle had no significant effect on peak UCOF values. For step turn, the propulsive force decreased with the increase of turning angle, which caused a result that the peak UCOF values of 60° turn were significantly greater than that for 90° turn. This suggests that turning angle had little effect on possibility of slip of spin turning but great effect on that of step turning, and the greater angle led smaller possibility of slip.
The purpose of this study is to determine how restricting inversion-eversion and pronation-supination motions of the ankle joint complex influences the stability of human gait. The experiment was carried out on a slippery level ground walkway. Spatiotemporal gait parameter, kinematics and kinetics data as well as utilized coefficient of friction (UCOF) were compared between two conditions, i.e. with restriction of the ankle joint complex inversion-eversion and pronation-supination motions (FIXED) and without restriction (FREE). The results showed that FIXED could lead to a significant increase in velocity and stride length and an obvious decrease in double support time. Furthermore, FIXED might affect the motion angle range of knee joint and ankle joint in the sagittal plane. In FIXED condition, UCOF was significantly increased, which could lead to an increase of slip probability and a decrease of gait stability. Hence, in the design of a walker, bipedal robot or prosthetic, the structure design which is used to achieve the ankle joint complex inversion-eversion and pronation-supination motions should be implemented.