The influence of forefoot bending stiffness of footwear on athletic injury and performance

Forefoot bending stiffness is a footwear property that has recently been gaining interest despite previously receiving limited attention compared to other footwear characteristics. This review focuses on relevant research studies examining the influence of forefoot bending stiffness on reducing injury and optimizing performance. Discussion of the current limitations and need for future research within the realm of forefoot bending stiffness is also highlighted. By reducing the amount of metatarsophalangeal extension, increased bending stiffness could not only reduce injury risk (e.g. turf-toe), but also serve as a treatment for metatarsal stress fractures by offloading the metatarsals. However, there are surprisingly limited in-depth studies examining how altered forefoot bending stiffness influences injury. Many unknown factors still need to be studied including the appropriate magnitude of bending stiffness and the influence that altering forefoot bending stiffness may have on the injury risk of other joints such as the ankle and knee. Forefoot bending stiffness can influence performance; however, the exact mechanism remains unclear. Early studies focused on foot energetics, while recent studies have shown the importance of altering the movement of the centre of pressure under the foot and the gearing ratio at the ankle joint. There appears to be a specific amount of forefoot bending stiffness for optimal performance. Future research should focus on identifying the exact mechanism of performance improvement with modified bending stiffness to help determine how this optimal stiffness can be identified.