KINEMATIC COMPARISON BETWEEN ATHLETES FROM THE INTERNATIONAL AND THE WORLD TAEKWONDO FEDERATIONS IN THE ROUNDHOUSE KICK

Taekwondo (TKD) is a combat sport organized by two main federations: International TKD (ITF) and the World TKD (WTF). The present study analyzed the kinematic differences in roundhouse kick performed by ITF and WTF athletes. Seventeen athletes participated in the study (8 ITF; 9 WTF). DVideo system was used to reconstruct the 3D coordinates of sixteen markers. Pelvis and hips angles and angular velocities were used to compare the groups. The results highlight two kick strategies to hit the target. WTF athletes performed the kick with increased pelvis left rotation while ITF used increased pelvis anteversion, hip flexion and abduction on supporting leg. These differences should be considered for adaptation of rules and training

KINEMATICS OF THE HAND AND KEY ROTATION IN A TENNIS FOREHAND DRIVE OF TENNIS PLAYERS

The purpose of the present study was to quantify kinematic variables of the hand of dominant arm and the main responsible rotation of the upper limb to the racket head velocity in an attack tennis forehand drive. Three elite tennis players and three highperformance tennis players were recorded with inertial measurement units (IMUs) with a frequency of 120 Hz during a cross-court (CC) and an inside-out (IO) forehand drive. The six fastest strokes in both directions were selected for analyses. Differences between two directions were shown in the follow through with a higher wrist abduction when playing in the inside-out direction (cross-court: 13.9 ± 17.2°; inside-out: 16.9 ± 18.6°). Results demonstrated that the horizontal flexion of the upper arm were the main responsible for the racket head velocity (48.1% CC and 45.2% IO)

Evaluation of upper limb joint contribution to racket head speed in elite tennis players using IMU sensors: comparison between the cross-court and inside-out attacking Forehand Drive

This study aimed to quantify and compare the upper limb angular kinematics and its contributions to the racket head speed between the cross-court (CC) and inside-out (IO) attacking tennis forehand of elite tennis players in a competitive environment. A new approach was used to study the forehand drive with mini-inertial sensors of motion capture to record the kinematic data. Six strokes in each direction per participant (72 shots in total) were chosen for analysis. Upper limb kinematics were calculated in the Visual 3D platform (Visual 3D Professional V5.01.21, C-motion, Germantown, MD, USA). The method used to calculate the upper limb’s contributions was performed with MATLAB software and used the segment’s (upper arm, forearm and hand) angular velocities and their respective displacement vectors obtained through the inertial sensors. Upper limb kinematics demonstrated a higher shoulder rotation in the IO direction with significant differences at the end of the backswing, which could be a key factor in distinguishing the two directions of the shot. Results also demonstrated that the horizontal flexion of the upper arm (around the shoulder joint) was primarily responsible for the racket velocity in the anteroposterior direction (48.1% CC and 45.2% IO), followed by the extension of the forearm (around the elbow joint) (17.3% CC and 20.9% IO) and the internal rotation of the upper arm (around the shoulder joint) (15.6% CC and 14.2% IO). No significant differences were shown in the contributions of upper limbs to the racket head velocity between the two directions of the shot. Tennis coaches and players should develop a specific training programme to perform higher angular velocities in these specific joint rotations.info:eu-repo/semantics/publishedVersio