抄録
The purpose of this study was to compare the maximal mechanical variables derived from loadvelocity (L-V) relationships and bat swing velocity (BSV) among collegiate baseball players, and to identify the L-V relationship variables more closely related to bat swing velocity. The participants were 40 male collegiate baseball players (age 20.5 ± 1.1 years, height 1.72 ± 0.05 m, body mass 71.2 ± 6.4 kg). BSV was measured using a swing measurement system with an inertial sensor attached to the bat grip end. The participants were categorized according to BSV relative to lean body mass into a high group (HG) and a low group (LG). The L-V relationship variables were determined for bench press (BP), squats, and high pull (HP) exercises. The lifting velocity was determined under 3 different external loads for each exercise. The relationship between load and velocity was expressed by a linear regression line. The intercept of the regression line with the vertical axis was taken as the maximal theoretical velocity (V0), and the intercept with the horizontal axis as the maximal theoretical load (L0). Power under the 3 different external loads was calculated for each exercise. The relationship between power and load was expressed by a second-degree polynomial model. The maximal theoretical power (peak power) was estimated as the apex of the parabola. For all participants, positive correlations with peak power were found for BSV in each exercise, V0 in BP, and L0 in HP. Of the L-V relationship variables, V0 in BP and L0 and peak power in HP were greater in the high group than in the low group. On the other hand, V0, L0, and peak power for squats were generally comparable between the groups. These results suggest that in baseball players, the L-V relationship is a practical means for assessment of maximal mechanical capacities, which are associated with the battingspecific performance of collegiate baseball players.
