The human hip joint is a common site of trauma and disease. Since the disease of the hip joint yields to immobility of the patient a considerable research has been directed toward understanding its development. It is acknowledged that the excessive mechanical loading may induce joint degeneration. The main biomechanical parameters which have been used to determine biomechanical status of the hip are the hip joint reaction force and the contact stress distribution in the hip joint articular surface. This book provides overview of methods that can be used to assess biomechanical variables acting in the human hip joint with emphasis on application of the results in practice. Described mathematical model of the hip joint reaction force is based on the static optimization approach while the hip contact stress distribution is estimated from the elasticity analysis. Mathematical modeling is applied to study normal and dysplastic hips during routine activities and to assess the stress distribution in hips subjected to avascular necrosis of the femoral head.