THE EFFECT OF THE INITIAL SHOULDER ANGLE AND ARM ANGULAR VELOCITY ON BALL SPEED DURING THE JUMP SERVE IN MALE HIGH-SCHOOL VOLLEYBALL STUDENTS AGED 16–18 YEARS IN BAGHDAD. JAREL [Internet]. 2026 Jun. 25 [cited 2026 Jul. 17];12(3):58-62. Available from: https://jarel.org/index.php/EL/article/view/43