Foot orthoses have been effective in the treatment of a variety of sport-related foot conditions. Although their use is well-established in clinical practice, many of the orthoses have not been evaluated in experimental conditions. Of the clinical studies that have examined the biomechanical changes associated with their use, many do not have predictable results. The failure of some studies to find trends for a particular variable does not preclude this variable being affected by the orthoses in an individual patient; rather, it may speak to the highly subject-specific responses with orthotic use. It is important to recognize that foot orthoses cannot be considered independent of a rehabilitation protocol that includes stretching and strengthening-specific therapies, as well as a consideration of training surfaces and training regimes. Additionally, foot orthoses must be considered in concert with the foot-wear recommendation.