Li Fengping, Sun Dong, Zhu Chengyuan, Zhang Qiaolin, Song Yang, Cen Xuanzhen, Xu Yining, Zheng Zhiyi, Gu Yaodong
Faculty of Sports Science, Ningbo University, Ningbo, China.
Doctoral School on Safety and Security Sciences, Óbuda University, Budapest, Hungary.
Comput Methods Biomech Biomed Engin. 2024 Sep 16:1-11. doi: 10.1080/10255842.2024.2402860.
The surge in popularity of running has led to a multitude of designs in running shoe technology, notably, there is an increasing trend in toe spring elevation. However, the impact of this design on foot structures during running remains an essential exploration. To investigate the effects of toe spring on the foot during forefoot running, we employed finite element simulation to create two sole models with different toe spring heights (6.5 cm and 8 cm) and ground contact angles (5°, 10°, and 15°). We established and validated two foot-shoe coupling models and compared stress variations in metatarsal bones and the big toe under identical loading and environmental conditions. Higher toe spring resulted in lower peak stress and reduced stress concentration in metatarsal bones. The fourth and fifth metatarsals exhibited increasing stress trends with ground contact angle, with the fifth metatarsal experiencing the most significant stress concentration. In the case of low toe spring, stress on the fifth metatarsal increased from 15.917 MPa (5°) to 27.791 MPa (15°), indicating a rise of 11.874 MPa. Conversely, the first metatarsal showed lower stress, indicating relative safety but reduced functional significance. Moreover, higher toe spring running shoes exerted less pressure on the big toe, with an increasing trend in stress on the big toe with an increase in ground contact angle. Shoes with a higher toe spring design result in reduced pressure on the big toe. Therefore, it is advisable to avoid landing angles greater than 15° to prevent stress fractures resulting from repetitive loading.
跑步热潮促使跑鞋技术出现了多种设计，值得注意的是，鞋头翘度升高的趋势日益明显。然而，这种设计在跑步过程中对足部结构的影响仍有待深入探究。为了研究前脚掌跑步时鞋头翘度对足部的影响，我们采用有限元模拟创建了两个具有不同鞋头翘度高度（6.5厘米和8厘米）以及地面接触角度（5°、10°和15°）的鞋底模型。我们建立并验证了两个足部与鞋子的耦合模型，并在相同的加载和环境条件下比较了跖骨和大脚趾的应力变化。较高的鞋头翘度导致跖骨的峰值应力降低且应力集中减少。第四和第五跖骨的应力随着地面接触角度的增加呈上升趋势，其中第五跖骨的应力集中最为显著。在鞋头翘度较低的情况下，第五跖骨上的应力从15.917兆帕（5°）增加到27.791兆帕（15°），增加了11.874兆帕。相反，第一跖骨的应力较低，表明相对安全但功能意义降低。此外，鞋头翘度较高的跑鞋对大脚趾施加的压力较小，大脚趾上的应力随着地面接触角度的增加呈上升趋势。鞋头翘度较高的设计会减少对大脚趾的压力。因此，建议避免着地角度大于15°，以防止因重复加载导致应力性骨折。
