Foot length is the key to determining shoe size and designing shoe lasts. Climate and activity intensity can affect foot length. Foot length is the key basis for determining shoe size, and at the same time, it is also an important reference for designing the base length of shoe lasts. However, during the design process, regardless of how the structure and style of the shoe last change, the sole length should always be slightly longer than the actual foot length. This design principle aims to ensure comfort and fit when wearing.
The length of the feet is not constant; it can be influenced by climate and the intensity of labor. Climate changes can cause the length of feet to expand when heated and contract when cooled, with the variation usually within 3 to 5 millimeters. When engaging in heavy physical labor or walking for a long time, the length of one's feet will also increase.
