| dc.description.abstract | INTRODUCTION: Coaches utilize verbal instruction to focus an athlete’s attention on pertinent aspects of a skill. Focus of attention can be classified as either internal or external (13). An internal instruction directs focus to bodily movements or the action itself whereas an external instruction pertains to the desired movement outcome, an implement (golf club, ball, etc.) or the environment (87, 13). PURPOSE: To compare the effect of internal and external focus of attention instructions on force-time characteristics of the countermovement jump (CMJ) in collegiate baseball players. METHODS: Forty-three resistance trained men ( ± SD; age = 20 ± 1.5 years; height = 186.4 ± 6.6 cm; body mass = 88.9 ± 8.8 kg) on an NCAA Division I baseball team volunteered to participate in this study. Each participant performed a total of 16 CMJs (2x4 jumps in both an internal and external focus condition). Jump height (JH), peak velocity (PV), mean concentric velocity (MCV), peak force (PF), mean concentric force (MCF), peak power (PP), mean concentric power (MCP), average eccentric rate of force development (ECC-RFD), relative mean concentric force (rCON) and relative net concentric impulse (rCON Impulse) were calculated from force-time and position data. Paired samples t-tests and Cohen’s d effect sizes were used to examine differences between conditions. Subjects also completed manipulation check surveys following each set of jumps. RESULTS: When subjects were instructed using an external focus they demonstrated significantly (p < 0.05) greater JH (48.0 ± 5.6 cm), PV (3.6 ± 0.3 m·s-1), MCV (2.31 ± 0.22 m·s-1), MCP (4,442.41 ± 716.35 W), ECC RFD (1,512.5 ± 249.1 N·s-1), and rCON impulse (3.4 ± 0.3 Ns·kg-1) as compared to jumps performed with the internal focus (46.4 ± 5.4 cm; 3.5 ± 0.3 m·s-1; 2.25 ± 0.23 m·s-1; 4,350.85 ± 729.79 W; 1,461. 2 ± 252. 8 N·s-1; 3.3 ± 0.3 Ns·kg-1). According to the manipulation checks, subjects adopted the desired focus of attention in 73.8% of the internal trials, and 66.6% in external trials. CONCLUSIONS: Trials in which subjects were instructed with an external focus of attention displayed significantly greater JH, PV, MCV, MCP, ECC-RFD, and rCON impulse. These results support the Constrained Action Hypothesis and related literature which state that external focus of attention enhances automaticity and subconscious control of motor patterns (101). It is interesting to note that there was superior recall of the internal instructions during the manipulation checks. This may suggest that the subjects thought about or consciously processed these instructions to a greater extent. Conscious processing may also explain the reduced internal condition performance. PRACTICAL APPLICATION: The present study demonstrates that several CMJ jump variables were significantly influenced by the stipulated instructions. These results indicate that instructions can alter the efficiency and performance of a skill and should be designed and applied appropriately. According to the literature and the present study, if an optimum performance metric (jump height, peak velocity) is desired, external focus of attention instructions should be used. | |
