## 4 Discussion
Among young participants, Strategy II appeared more favorable for kinematic parameters, even though Strategy I was more frequently chosen. In older adults, Strategy II again seemed preferable for kinematics, but Strategy III showed the least deviation from unperturbed gait for kinetic parameters, making Strategy I still the most favorable globally for this group. Overall, these results emphasize that while younger and older adults show similar patterns of strategic response to perturbations, the specific biomechanical adjustments differ significantly, likely reflecting age-related changes in neuromuscular control and mechanical efficiency. Analyzing the available literature on this topic, it is noteworthy that most authors have focused on the impact of gait perturbations primarily in the context of maintaining stability. This focus has led to the quantification of an individual's ability to control the center of mass (CoM) relative to the base of support (BoS), using measures such as stabilizing and destabilizing forces, feasible stability regions, and margins of stability (MoS) [45; 52; 53]. While some studies have examined changes in spatiotemporal parameters [53; 54], their approaches vary depending on the type and timing of the applied perturbation. In contrast, this study provides novel insights through a comprehensive analysis of vertical ground reaction force patterns and their corresponding kinematic and kinetic adaptations, assessed separately for both the perturbed and reactive limbs. These findings have important clinical implications, particularly for fall prevention and rehabilitation in older adults. By identifying distinct compensatory strategies in response to perturbations and revealing age-related differences in joint loading and movement patterns, this study underscores the need for targeted, population-specific interventions. Training programs could be developed to improve neuromuscular control and promote more stable and adaptive gait responses in older individuals. For example, incorporating perturbation-based balance training into rehabilitation routines may help elderly individuals adopt more efficient strategies, thereby reducing fall risk. Moreover, the strategy classification approach proposed here may be used as a tool to monitor therapeutic progress or assess fall risk in clinical settings. Personalized rehabilitation plans could then be formulated based on individual biomechanical deficits, enhancing the precision and effectiveness of intervention strategies. This study has some limitations. First, only women were included. Given that older women experience more severe fall consequences than men, this is important clinically; however, including men in future studies would be valuable. Secondly, gait and perturbation parameters differed between groups because the natural comfort speed for each participant was used to maintain a natural gait pattern. Thirdly, strategies were analyzed separately for the perturbed and reactive limbs. Future research should consider analyzing these strategies together, possibly including trunk and upper limb movements to gain a more complete understanding of global motor strategies for fall avoidance. Finally, the last limitation of this study is that only one type of perturbation was examined and analyzed, which limits the ability to compare the results with other studies. Therefore, it is necessary to investigate different types of perturbations to broaden the understanding of this topic.