Biomechanical Analysis Of Risk Factors Of Ankle Injury In Basketball Players With Two Different Landing Modes

Research objective: Most technical movements in basketball end with landing.Studies have shown that the rate of sports injury occurs in the landing stage is high,and different landing modes affect the location and incidence of injury through different biomechanical mechanisms.Most of the researches on basketball fall injury are on knee joint,but few researches on ankle joint,which is equally important and easily injured.In this study,the biomechanical experiment method of simultaneous combination of kinematics and dynamics was used to compare the differences of lower limb joint parameters of basketball players in different landing modes,and to explore the injury mechanism of ankle joints in different landing modes,so as to provide theoretical basis and guidance for practical training.Research methods: Ten second-level male basketball players were selected as the experimental objects,and the landing movements were divided into two landing modes: running emergency stop,two-leg jump,front foot landing and running emergency stop,two-leg jump,and foot landing.The 3d kinematics and dynamics data of experimental objects were collected and analyzed by motion capture system and 3d force measuring table.The results were as follows: 1)The initial landing Angle of forefoot was larger than that of hip flexion,hip adduction,knee bend,knee varus,ankle plantar flexion and medial ankle rotation（P < 0.05）,and smaller than that of ankle dorsiflexion（P <0.01）.2)Joint peak Angle: forefoot landing had larger peak Angle of hip flexion,ankle plantar flexion,and ankle varus（P < 0.05）,smaller peak Angle of hip abduction,knee extension,ankle dorsiflexion,and ankle internal rotation（P < 0.05）;3)Range of joint motion: forefoot landing had a smaller range of hip flexion and extension,knee flexion and knee flexion,ankle dorsiflexion and plantar flexion（P < 0.05）,and a larger range of ankle valgus and valgus（P < 0.01）;4)Joint torque: the front foot landing has higher peak bending torque and ankle plantar flexion torque（P < 0.05）,and smaller peak bending torque and ankle dorsiflexion torque（P < 0.05）;5)Ground reaction force: the forward peak ground reaction force was larger when the forefoot landed（P < 0.05）,and the outward peak ground reaction force was smaller（P < 0.05）;There was no significant difference in other indexes between the two landing modes（P > 0.05）.Conclusions: 1)There are differences in kinematics between the two landing modes.Forefoot landing has a larger plantar flexion and varus Angle of ankle joint and a smaller range of motion of lower limb joint flexion,which may increase the risk of ankle injury during landing.The smaller knee bend Angle of the rear foot landing may increase the load on the patella and increase the risk of knee injury;2)There are differences in dynamics between the two landing modes.Forefoot landing with higher ankle plantar-flexion torque and lower knee extensor torque may increase the risk of ankle injury during landing.Forefoot landing with higher impact force in the horizontal direction may increase the risk of Achilles tendon injury and metatarsal fracture;Rear-foot landing with greater knee extension torque may increase the risk of knee and calcaneal injuries.