Annals of Applied Sport Science

Background. The aim of this study was to analyze of core muscle fatigue effects on the kinematic parameters change during volleyball jump serve. Methods. The participants were sixteen experienced male volleyball player, with average age, height, and body weight of 24.6 ± 1.8 years, 1.85 ± 1.6 m, and 79.5 ± 3.5 kg, respectively. This study utilized two high-resolution video cameras, a drone video, a lactate analyzer, and a radar speed gun. Meanwhile, the eight kinematics parameters analyzed at the approach, plant, and jump phases showed the ball speed decreased significantly in the fatigue condition, compared to the non-fatigue counterpart. Results. There was a significant difference in the jump phase duration, step length, and jump height variables for the under fatigue and non-fatigue conditions, during the jump serve in volleyball. Furthermore, the six kinematics parameters analyzed in the maximal shoulder external rotation phase showed significant difference in fatigue and non-fatigue conditions were found in the shoulder external rotation and trunk tilt backward parameters. Meanwhile, the In the maximum angular velocity phase at the upper limb joint, during the jump serve, showed the variable shoulder internal rotation decreases significantly in the fatigue condition, compared to the non-fatigue counterparts. Also, in the trunk rotation and trunk tilt forward, a significant decrease in the upper limb joint’s maximum angular velocity was observed in the fatigue condition during the volleyball jump serve. Conclusion. Fatigue reduces players’ performances during jump serve in volleyball, thereby leading to slower ball speed and changes in body segment movements.