Methods: Relevant databases (PubMed and SCOPUS) were searched. A total of 123 young athletes (aged 9-12 years) will be evaluated. Subjects will be tested biomechanical analysis including all relevant angles, as follows: the Helbing angle, the femorotibial angle, and the Fick angle in both limbs. Subjects will be divided into two groups at random. Children in experimental group will participate in an exercise program for three months. Children in control group will not received treatment for three months. After the study, these children will receive the same treatment as children in experimental group.