# Research on Kinematic Parameters of Multiple Gait Pattern Transitions
## 1 Introduction  
In the real world, we encounter complex road conditions; therefore, in the practical application of exoskeletons, we also need to take into account these conditions. Gait recognition technology is the premise that exoskeletons can cooperate with the wearer to walk and transition smoothly in a complex terrain environment and achieve a labor-saving purpose. In reality, when healthy people walk between different terrains, they adjusttheir gait strategy in time before each terrain transition in order to better maintain balance and ensure a safe and stable completion of the transition. The purpose of this study is to systematically analyze the kinematic parameters of an individual prior to the completion of a gait transition, to identify which kinematic parameters have significant differences in the transition stride when compared to the stride of a former gait pattern during a variety of gait transitions, and to determine the order the significant differences occur. This study is expected to provide a better basis for the recognition of the gait transition of the human-exoskeleton system in different terrains. At present, the research on gait recognition in the field of exoskeletons mainly focuses on gait recognition under each terrain (pattern), including the basic research of biomechanics and the research of a recognition algorithm [1; 2; 3; 4]. However, there are few studies on gait pattern transition, and the recognition of gait pattern transition affects the effect of human-robot cooperation. Among them, the [PERSON] team of Tianjin University of Science and Technology studied the biomechanical characteristics of lower limbs during stair walking, which provided the basis for the selection of exoskeleton driving elements and gait planning [5; 6]. Gait transition recognition has been mentioned in some studies [7]; however, there is no systematic study and analysis of the available parameter information. Gait transition between level and stairs was studied by [PERSON] et al. in Germany, who analyzed whether there is a transition phase between level and stairs, the duration of the transition phase, and whether there is a joint-related order and timing for the start and end of the transitions. The study was carried out in order to provide reference for the control concept design and performance of a lower limb exoskeleton or prosthesis and to achieve the purpose of improving transition smoothness [8]. In the field of medicine, there are also many related studies that study and analyze the gait strategy of healthy individuals walking on different terrains, including the regular changes in kinematic, kinetic, and spatiotemporal parameters of the lower limbs and trunk in walking up and down stairs and slopes [9; 10; 11]. Among them, [PERSON] et al. found that it is possible to distinguish between level walking and stair ambulation based on the kinematic parameters of the trunk [12]. In the literature [13; 14], it was also pointed out that at different walking speeds the trunk movement has a corresponding change. Therefore, the kinematic and kinetic parameters of the lower limbs and trunk are of great significance for the study of gait pattern transition recognition. In addition, there have been many studies on the transitions between level and slopes, between level and stairs, and between walking and running [15; 16; 17]. [PERSON] et al. found that during the transition from walking to running, the kinetic variables showed nonlinear behavior, and the joint kinetic measures actively change in nonlinear patterns before running to prepare for the gait transition. A team at Pennsylvania State University studied the spatiotemporal parameters of the transition between level and ramp, including walking speed, stride length, etc., and concluded that healthy young adults adopt a unique gait strategy different from both level and slope walking during transition strides [15].