The Biomechanical Analysis Of Men’s Sanda Athletes Front Leg Positive Kick Action

Front kick is one of the main leg kicking techniques for Sanshou athletes, whilethere is less biomechanical researches on front kick at present. This paper usesVICON motion capture analysis system, Kistler three-dimensional measuring forceplatform and multi-functional dynamometer target to measure related indicators: theaction time, angle of trunk rotation, striking legs’ joint angle, link speed, angularvelocity, ground reaction force of supporting legs and so on in the Sanshou athletes’front kick striking process to investigate the main factors that may influence Sanshouathletes’ front kick striking effects. The study shows:1. For the relative combat effectiveness of Sanda front leg kick, excellent groupis about4.48KG, ordinary group is about3.44KG, thus excellent group’s relativecombat effectiveness is better than normal group. The time of knee lifting stage,stretching stage and hitting stage and the total time, it’s0.32seconds,0.07seconds,0.10seconds,0.49seconds for excellent proup, and it’s0.35seconds,0.08seconds,0.09seconds0.52seconds for normal group, except the hitting stage, excellent groupis faster than normal group in other two satges’ time and total time.2.The trunk rotation angle of the three stages, the angles of normal group are2.78degrees,7.98degrees,14.84degrees, normal group are4.84degrees,6.85degrees,10.34degrees, except excellent group is smaller than normal gropu duringknee lifting stage, excellent group is better than normal group in other stages. For thein addition to excellent group stage knee than normal group, other groups wereexcellent stage than an ordinary group. The trunk rotation angular velocity of the threestages, it’s around185degrees/sec,233°/sec,225°/sec in excellent group, whichis faster than nromal group:142degrees/sec,171°/sec,139°/s or so.3.The attacking legs’ angles for hip, knee and ankle at critical moment ofexcelent group’s knee lifting stage are around86degrees,102degrees,95degrees,while it’s87degrees,101degrees,94degrees. For strething stage, it’s about99degrees,143degrees,99degrees for normal group, it’s about102degrees,152degrees,106degrees for normal group. During hitting stage, it’s about122degrees,179degrees,115degrees, while it’s about117degrees,169degrees,119degrees.According to the features of Sanda front kick action, excellent group has morereasonable joint angles in each stage than normal group.4.For attacking legs’ the peak value of linear velocity, it’s about31m/s、3.8m/s、5.94m/s for excellent group’ hip, knee and ankle in knee lifting stage, it’s about1.26m/s、3.87m/s、6.01m/s for normal group. In stretching stage, attacking legs’ the peakvalue of linear velocity on hip, knee and ankle, it’s about1.43m/s、1.93m/s、5.54m/sfor excellent group, it’s about1.23m/s、2.18m/s、5.81m/s for normal group. In hitting stage, it’s about1.81m/s、1.73m/s、1.32m/s for excellent group, normalgroup is1.31m/s、1.45m/s、1.10m/s. In the knee lifting stage, stretching stage andhitting stage, excellent group has higher hip peak value of linear velocity, whileexcellent group has bigger joint angular velocity in different stages.5.The absolute gravity displacement of excellent group in different stages isabout0.09m、0.07m、0.06m, normal group’s absolute gravity displacement is about0.08m、0.07m、0.07m, the excellent group’s peak value of gravity speed in differentstages is about0.61m/s、0.38m/s、0.42m/s, for normal group, it’s about0.62m/s、0.31m/s、0.28m/s, the excellent group’s gravity displacement is higher than normalgroup in knee lifting stage, excellent group has higher gravity speed in stretching andhitting stage.6.The relative to the ground reaction force of excellent group’supporting legs indifferent stages of front kicking movements is about14.66N/kg,14.12N/kg,20.66N/kg, while normal group is about16.62N/kg,13.57N/kg,16.54around N/kg.In the knee lifting stage, the relative to the ground reaction force of normal group isbigger than normal group, while in the stretching and hitting stage, the relative to theground reaction force of normal group is smaller than excellent group. The jointtorque of excellent group is bigger than normal group.7. The higher degrees of muscle activation about attacking legs in differentstages are rectus femoris, musculus vastus medialis, musculus vastus lateralis andmusculi gastrocnemius, while the higher degrees of muscle activation of supportinglegs are also rectus femoris, musculus vastus medialis, musculus vastus lateralis.