# A New Inspiration in Bionic Shock Absorption Midsole Design and Engineering
## 3 Results and Discussion
### Physics Tests and Numerical Simulations
#### 3.3.3 Plantar Pressure Tests  
The results show that the highest plantar pressure was in the forefoot area under all conditions, and the peak plantar pressure was lower with the bionic midsole shoe. Except for the arch area, the peak plantar pressure in the different plantar areas was lower for the bionic midsole than for the conventional midsole. Our results show that during walking and brisk walking with the bionic midsole shoe, the peak pressure in the forefoot area decreased by 10.59% and 8.35%, respectively, and that in the heel area, it decreased by 12.27% and 6.04%, respectively, while the peak force in the forefoot area decreased by 10.31% and 8.62%, respectively, and that in the heel area decreased by 16.03% and 14.47%, respectively. The average pressure in the forefoot area during walking and brisk walking decreased by 7.95% and 7.88%, respectively, and that in the heel area decreased by 8.92% and 7.36%, respectively, while the pressure-time integral in the forefoot area decreased by 4.23% and 4.06%, respectively, and that in the heel area decreased by 10.58% and 10.29%, respectively. The force-time integral in the forefoot area during walking and brisk walking decreased by 12.66% and 6.91%, respectively, and that in the heel area decreased by 3.06% and 5.72%, respectively. Plantar pressure is a key factor in evaluating shoe comfort which also represents the shock absorption ability of sports shoes. Such sports shoes with better shock absorption function show decreased plantar pressure and impact energy transfer to the body and joints [27]; otherwise, a larger impact force additionally increases the injury risk and makes wearing shoes feel uncomfortable [13; 14; 28]. Higher plantar pressure in the forefoot during running may be related to metatarsal injuries [29], and evenly distributed plantar pressure is beneficial for foot health [2; 11]. The results show that the bionic midsole did show a better shock absorption ability compared with the conventional midsole, especially in the forefoot and heel areas. During the walking and brisk walking tasks, the bionic midsole showed better shock absorption performance in plantar pressure, which indicated that the bionic midsole would likely be more comfortable. For the higher impact force in forefoot area, we believe this was attributed to the reaction force during the push-off phase. The bionic midsole decreased the push-off force during the walking tasks, which needs further research to investigate the influence on exercise or sports. The present research provides a new design idea via the ostrich toe pad structure and the development of a shoe midsole to better protect the feet during daily physical activity. This represents a considerable advance in shoe manufacturing. The pressure-time integral and force-time integral indicate the cumulative situation of plantar loading, presenting the energy consumption of foot strikes during walking and brisk walking. Exorbitant integral values indicate the poor shock absorption ability of the midsoles, increasing the risk of potential injuries in lower extremity skeletal tissues [30]. [PERSON] et al. (1987) [31] indicated that during running, the higher force loading in the forefoot that makes the impact force swiftly rise to its peak is also believed to have a connection to running-related injuries [32]. A higher contact area or better shock absorption by the midsole could help runners to temporarily avoid lower extremity overload risks [33]. Our results indicate that the bionic midsole had better shock-absorption of the planta pressure compared with the conventional midsole. A runner's joints may adapt to the stimulation of internal and external forces [33], but the adaptation may not be able to prevent injury factors for a prolonged period. Whether a bionic shock absorption midsole is better for sustained physical activity requires further investigation. There are some limitations in the present research that should be mentioned.