少棒選手內、外角球打擊動作分析

Abstract

背景：打擊表現在棒球賽中扮演著左右勝負的重要因素，為了壓制對方打線，投手通常會投出打者較難有效掌握擊球的內、外角球來應對，而國內相關研究以慣性感測器研究少棒打擊動作技術較為缺乏。目的：本研究盼透過穿戴式裝置 (IMU) 分析少棒選手打擊內、外角球不同球路時，髖部、軀幹以及手部運動學參數，並從中分析打擊動作技術，為教練與選手提供實用參考之價值，有助於球員往後運動生涯的發展。方法：以17位少棒選手參與實驗，分別黏貼六顆IMU於受試者髖部、胸骨、雙手上臂及雙手手腕。每位受試者成功揮擊打擊座上之固定位內、外角球與自由位內、外角球四種位置各5顆，共20顆。所測得之各肢段動作時序及軀幹旋轉角速度峰值，使用SPSS 23.0統計軟體分析，統計檢驗的顯著水準之α值定義為p< .05，以單因子相依樣本變異數分析四種打擊位置與打擊結果間的運動學差異。結果：受試者之各肢段動作時序合加速度峰值及軀幹旋轉角速度峰值平均數 (上背部：F = 1.976，p > .05；下背部：F = 0.808，p > .05) 皆與四種打擊位置之打擊結果呈現無顯著性差異。結論：肢段合加速度峰值及軀幹旋轉角速度峰值皆與四種打擊位置之打擊結果之間無直接或間接的關聯性，建議未來研究可實驗不同層級或階段之選手，以驗證是否有同樣的發現。Background: Batting performance is crucial in baseball games. Pitchers often use inside and outside corner pitches to challenge batters. However, research on youth baseball batting techniques using inertial sensors is limited. Purpose: This study aims to analyze the kinematic parameters of the hips, torso, and hands of youth baseball players when hitting inside and outside corner pitches using wearable IMUs, providing practical insights for coaches and players. Methods: Seventeen youth baseball players participated in the experiment. Six IMUs were attached to the subjects' hips, sternum, upper arms, and wrists. Each participant successfully hit five balls each from fixed inside, fixed outside, free inside, and free outside positions, totaling 20 hits. The collected kinematic data, including segmental motion timing and peak trunk rotational velocity, were analyzed using SPSS 23.0, with a significance level set at p < .05. Repeated measures ANOVA was used to examine the differences between the four batting positions and their results. Results: The average peak values of segmental acceleration and trunk rotational velocity (upper back: F = 1.976, p> .05; lower back: F = 0.808, p > .05) showed no significant differences across the four batting positions. Conclusion: There is no direct or indirect relationship between the peak segmental acceleration, trunk rotational velocity, and the results of the four batting positions. Future research should explore different levels or stages of players to verify these findings.