부산대학교 도서관

Background: Understanding how manipulating variables with vertical jump instruction could influence kinetic variables would be beneficial for trainers and athletes. External focus (EF) instructions have been shown to result in superior motor performance compared to an internal focus (IF). Objective: In this study, we tried to determine the effects of verbal instructions using IF and EF of attention on some kinetic characteristics of three different vertical countermovement jumps (CMJs). Methods: Ninety male participants (age, 23.9 ± 2 years; height, 178.7 ± 4 cm; and mass, 74.2 ± 7.5 kg) were randomly assigned into IF (n = 30), EF (n = 30), and control groups (n = 30) and were given specific instructions. Subjects performed three kinds of CMJs on a force platform: (1) short countermovement jump (S-CMJ), (2) natural countermovement jump (N-CMJ), and (3) deep countermovement jump (D-CMJ). Landing kinetic (displacement, force, leg stiffness, and center of pressure (COP) to center of mass (COM) displacement) variables from the CMJs were assessed for pre, post training, and retention test (1 week later). Results: The results showed that EF instruction could significantly improve vertical CMJ kinetic variables. Retention was achieved and vertical CMJ kinetic variables were maintained for subjects in the EF group. Conclusions: This study showed that using EF instructions improved vertical CMJ kinetics compared to IF instructions. EF is suggested to apply to CMJs for improving performance based on the exact athletic demands. [ABSTRACT FROM AUTHOR]