The purposes of this study were to analyze the kinematics and electromyographic variables of the upper
extremity for the backhand clear motion between elementary school players group and high school players
group. Six elite male elementary school players and six elite male high school players were selected as the
subjects. Four digital video cameras and Noraxon Telemyo 2400 were used to collect the 3D kinematics and
electromyographic data. The results were as follows : 1) in the phase of backswing, elementary school players
showed shoulder rotation angle of 136.30±18.99 degrees, elbow rotation angle of 106.28±12.76 degrees and also
showed larger average electromyography in trapezius and triceps brachii. 2) in the phase of impact,
elementary school players showed wrist angle of 146.30±8.27 degrees, maximum wrist angular velocity of
817.99±114.06 degree/sec. These values imply that elementary school players were faster than high school
players in wrist angular velocity and they had larger average electromyography in wrist extensor and
trapezius. 3) in phase of follow-through, elementary school players showed larger wrist extensor and trapezius
in electromyography than high school players. 4) in velocity of racket head, elementary school players showed
22.18±5.41 m/sec, high school players showed 33.31±7.51 m/sec and elementary school players showed smaller
value than high school players.