The major components of a shoe can be broken down as illustrated in figure 1. Each part, in turn, can be broken down into smaller sub-components. It's also important to note that, even though the shoe can be broken down into these four major components, and one can apply science to help improve the design of each, all of these parts operate in an integrated fashion. What follows then is an overview of these main components, their key sub-components, and the properties sports researchers study relative to their performance. Also included are some current ideas relative to design that might be incorporated into the part to improve performance. Lastly, where appropriate, a brief introduction to the history behind the evolution of the components design is provided.
The major parts of a shoe.

1. Upper
2. Insert
3. Midsole
4. Outsole