## 4 Discussion
Although angular velocity changes occur, the body may maintain the stability of movement angles by adjusting other kinetic parameters (such as muscle strength utilization or coordination of other joints), thus optimizing movement efficiency. This design can enhance runners' adaptability under specific conditions, such as uneven surfaces or inclined tracks, where running in such unstable conditions may stimulate muscle groups related to the lower limbs and enhance the coordination ability of the ankle joint and surrounding muscles. Studies have shown that the unstable design of biomimeticshoes helps strengthen muscle control, enhance postural stability, and proprioceptive ability [31]. Under such conditions of unbalanced load distribution, the muscles, ligaments, and joints of the lower limb need to adapt to the altered mechanical environment in different ways, which may lead to changes in the overall distribution pattern of moment and power. Through the analysis of knee joint moment during the landing and push-off phases, we found that, compared to NS, there were significant differences in knee flexion moment under the L6 condition, with a significant reduction in the peak moment during the push-off phase, potentially reducing the risk of knee cartilage damage and contributing positively to the prevention of knee pain and degenerative diseases such as osteoarthritis. As demonstrated in a study, 6 mm lateral wedge insoles significantly reduced pain in patients with grade II and III knee osteoarthritis during walking, standing, resting, and knee joint movement [32], and it has been shown that patients with knee osteoarthritis have unique plantar pressure patterns during walking, with lateral wedge insoles being one of the treatment options [33]. We believe that the design of L6 may shift the lower limb load from the knee joint to other joints, such as the hip or ankle joint. Studies have shown that when running in minimalist shoes, joint work is redistributed from the knee to the ankle [34], which is consistent with the increased ankle dorsiflexion moment described earlier. Such shoe design may assist runners in moving more efficiently. As demonstrated in the results shown in Table 2, knee joint extension work significantly decreased under the L6 condition compared to NS. This transfer of energy contributes to overall running efficiency improvement and reduces the risk of knee joint injury. In the L6 condition, we observed significant differences in the hip joint's flexion-extension moment during the stance phase, with notable increases in peak moments during both the landing and push-off phases. Our analysis of experimental results revealed a significant increase in hip joint extension work. Besides the previously mentioned load distribution, we speculate that the design featuring a higher lateral forefoot alters the force line during foot landing and propulsion, potentially requiring more hip joint force to maintain balance and stability, especially necessitating increased extension work during propulsion. The increase in work implies a greater transfer of power to the hip joint musculature to accommodate the biomechanical changes induced by the new shoe condition. Additionally, under the M9 condition, we observed reductions in the hip joint's abduction-adduction peak moment, power, and work in the sagittal plane. Such design alterations may enhance foot stability, reducing the additional force required to maintain balance during hip abduction. Studies suggest that reducing the abduction moment at the hip joint during standing is crucial for preventing the progression of hip osteoarthritis [35]. Lowering the load during abduction movements can decrease the risk of damage to surrounding soft tissues, such as hip muscles and ligaments, thereby reducing the incidence of muscle strains and ligament injuries. These findings have important implications for the health and long-term running habits of runners.