Task: Question Generation
Input (English): In a tumbling pass, dismount or vault, landing is the final phase, following take off and flight  This is a critical skill in terms of execution in competition scores, general performance, and injury occurrence. Without the necessary magnitude of energy dissipation during impact, the risk of sustaining injuries during somersaulting increases. These injuries commonly occur at the lower extremities such as: cartilage lesions, ligament tears, and bone bruises/fractures. To avoid such injuries, and to receive a high performance score, proper technique must be used by the gymnast. "The subsequent ground contact or impact landing phase must be achieved using a safe, aesthetic and well-executed double foot landing."  A successful landing in gymnastics is classified as soft, meaning the knee and hip joints are at greater than 63 degrees of flexion.
Output (English): What is a successful landing?