Successful return to work or athletic sports after rehabilitation of an orthopeadic condition and sports injury of the lower extremities requires that the therapist understand the mechanical requirements of high level Physical activity. High level Physical activity need resistance exercise Program in the treatment approaching methods. One of them, the plyometrics training is the best way that will be magnifing the musculotendon unit. So it is important understanding of biomechanics and neurophysiology of plyometrics.