Kinematics and Relatively Muscle sEMG Analysis on the Punch-impact Phase in Back Straight Punch of Chinese Male Elite Boxers

The purpose of this study was to analysis kinematics and relatively muscle sEMG features on punch-impact phase in back straight punch of male boxing elites of China and provide the basis for specialization muscle training.Methods:Three-dimensional video graphic and synchronism surface electromyography telemetry were collected from 6 male elite boxers performing back straight punch at their maximum effort.Results:Muscle sequencing in punch-impact phase were:gastrocnemius→biceps femoris→deltoid toe→triceps brachii→biceps brachii→brachioradialis.Deltoid toe,biceps brachii and triceps brachii in corresponding time position appears distinct pre-activation and co-activation.According to muscle work/Loading Percent in punch-impact phase,deltoid toetriceps brachiibiceps femorisgastrocnemiusbrachioradialisbiceps brachii;aEMG result keep the trend with the muscle work/loading percent.During punch-impact phase,shoulder joint,centroid of upper arm and hand peak velocity increase in turn at chronological order.Conclusions:In punch-impact phase,muscle activation sequencing demonstrated from low to upper limbs,deltoid toe,biceps brachii and triceps brachii's pre-activation and co-activation worth to concern.In muscle work/load percent and aEMG,deltoid toe,triceps brachii and biceps femoris are important in punch-impact phase.There is a reasonable correlation of anatomy between upper limb muscles activity sequencing and shoulder joint,centroid of upper arm、hand peak velocity order,also causes of open chain whip in upper limb.