Abstract: Both high difficulty and high quality movements, especially series of such movements are encouraged by the new gymnastics rules. This present paper collected by means of 3D video analysis kinematic data of back somersault with three twists and 3/2 twists in competitions, and then reproduced the actual movements through modelling simulation for an analysis of the key kinematic and kinetic features of landing. The results showed the athletes successfully completed the series of actions and landed steadily. An excellent body posture angle during the first landing contributed to a quick brake and take-off. Muscles of knee and hip joint were the played a major role in resisting the impact force. In addition, body rotation continued after landing. As a result, loading on the two lower limbs was significantly different, and this may pose a high injury risk. During the second landing, the body posture angle was smaller, but it was not conducive to landing stability. The athletes had excellent control ability and maintained balance with greater knee flexion and thus kept standing successfully.

Key words: floor exercise, back somersault with 3 Twists and 3/2 Twists, landing, kinematics, kinetics, modelling simulation