Gait patterns during tripping in young adult males: Unconscious selection of recovery strategy depending on the relative position of the center of mass (CoM) and base of support (BoS)

This study investigated gait recovery strategies in response to obstacle-induced tripping among young adult males, focusing on the interaction between the base of support (BoS) and the center of mass (CoM). Four primary recovery strategies were identified and classified: Elevating-in (E-in), elevating-out (E-out), lowering-in (L-in), and lowering-out (L-out). Our findings reveal a crucial correlation between the position of the CoM and the supporting foot during tripping incidents, which significantly influences the choice of recovery strategy. Detailed analysis of activation timings within the elevating and lowering strategies during the swing phase confirmed the effectiveness of classifying these strategies based on the relative positions of the BoS and CoM. The elevating strategy, particularly when the supporting foot is near the obstacle and the CoM is within the BoS, shows an increased risk of falling. Furthermore, the activation timings for both elevating and lowering strategies across the swing phase were consistent with previous research, validating the classification of four distinct strategies rather than the traditionally recognized three. These findings highlight the essential role of the positional relationship between the BoS and CoM in selecting appropriate recovery strategies. This study provides critical insights that can enhance the development of fall prevention programs and improve gait stability, offering new approaches for designing assistive devices and training programs aimed at reducing fall risks during gait interruptions caused by obstacles. Future research will build on these findings to develop more effective fall prevention strategies and interventions.