Mesa AZ ORTHOTICS
One of the most common reasons that clinicians recommend inserts and orthotics is to act against a developing injury or avoid a typical movement-related injury. Orthotics have been proposed for many different problems and injuries, including diabetes, flat feet, osteoarthritis and rheumatoid foot disease, although the precise function these devices provide remains unclear.
This paper proposes a new theory for the utility of inserts and orthotics for sports activities.
Based upon a review of research studies, the authors state that the primary function of orthotics or inserts may not be to align the skeleton or provide impact cushioning. The authors propose instead that orthotics minimize muscle work whereby the orthotic supports a preferred movement path, reducing muscle activity and, in doing so, increasing athletic performance.
Their model takes into account many variables, including the athlete, the movement task, the shoe and the orthotic. Using this model, the authors hope to match subject characteristics with orthotic characteristics to develop the optimal orthotic fitting.
Nigg BM, Nurse MA, Stefanyshyn DJ. Shoe inserts and orthotics for sport and physical activities. Medicine&Science; in Sports&Exercise 1999:31(7-suppl.), ppS421-S428 
