PUB - Publikationen an der Universität Bielefeld

Safe and reliable locomotion is a fundamental aspect of human life, involving adaptive responses to environmental disturbances such as obstacles or slopes. With obstacle-related falls being a leading cause of injury, particularly among older adults, it is crucial to understand the processes underlying successful obstacle traversal in humans.

This thesis investigates and quantifies the effects of slope on human obstacle traversal — a facet largely overlooked in preceding studies. It investigates the complexities of the interaction of slope on the one hand and spatial disturbance by means of obstacles on the other. With a focus on this interaction, it provides comparative insights into differences between walking and running, thus broadening the understanding of biomechanical adaptations to variable terrain.

The approach taken by this thesis rests on two methodological improvements:

1. the Interactive Locomotion Lab (ILL), a state-of-the art laboratory for studying human locomotion, combines Virtual Reality (VR), motion-capturing and a six-degrees-of-freedom motion-base, allowing precise and repeatable measurements and a wide range of study-specific experimental designs. 2. the use of advanced statistical modelling techniques, to analyse the relative effects of multiple factors and their interactions on recorded time-series.

The combination of these methods allowed us to tell apart slope-dependent from obstacle-dependent effects and resulted in findings that challenge common findings, such as lift-off distances being constant across wide ranges of conditions. Instead, here, we show that lift-off distance increases with slope. With respect to gaits, we show uni-directional inter-gait learning transfers, supporting the theory that walking and running are manifestations of the same underlying control system.

In conclusion, this thesis emphasizes the relevance of slope in human obsta- cle traversal — an aspect which has not been fully addressed in prior research. Our findings demonstrate that slope significantly impacts key aspects of human obsta- cle traversal, inviting consideration of this factor in past and future studies, thus refining our understanding of obstacle traversal dynamics. As we advance in this field, further investigations could explore the influence of diverse slope conditions on gait and obstacle negotiation, thereby enabling advances in other fields such as robotics, fall-prevention or urban planning.