Why do we need the orthotic? It makes the system difficult to use. Ease of use was a driving factor in the design of the TAOS. The orthotic does add complexity but it is a necessary element of the system. The goal of the orthotic is to place the legs in the best position for walking. Once properly oriented the child can fire the appropriate muscles to walk. Unwanted movement is restricted and helps to train the appropriate muscles. Without the orthotic we see children "learning" to use the wrong muscles. Outside of an orthotic children often use hip adductors to swing their leg forward. Not only are we training the wrong muscle, but this overuse of a muscle not normally used in gait cascades into a whole other set of problems.