以動態光點探討羽球正拍擊球動作訊息

Abstract

本研究的目的在透過動態光點的模式，針對羽球正拍擊球動作所產生的恆定性訊息進行分析探討。主要分為兩個實驗，實驗動作者為各6名羽球專長及非專長者，使用陀螺儀（GypsyGyro-18）及高速攝影機（200 Hz）拍攝墜球、殺球及高遠球正拍擊球動作，事後再將影片轉換為15個關節點的動態光點影片。實驗一：專家25名和非專家33名觀看144段動態光點影片，依據羽球擊球預備動作來判斷落點，結果顯示兩組雖無法精確判斷擊球落點，但仍有部分恆定訊息可做為推測的依據，專長選手辨識能力略優於非專長者，而辨識球路的得分率顯著高於辨識方向。實驗二：實驗動作者觀看72段動態光點影片，依據羽球擊球完整動作來判斷是否為自己的擊球動作，結果顯示動作者無法辨識自己的擊球動作型態，而且非專長者傾向將專長選手的動作誤認為自己的動作。綜合實驗結果，透過動態光點可提供與動作有關，但與個人特徵無關的重要訊息，而環境中訊息的恆定性是具有訊息模式的特殊性，環境賦使會影響對特殊訊息模式的偵測。The purpose of this study was to examine the invariant information of badminton forehand shots from dynamic point light data alone. A motion digitizing system (GypsyGyro-18) and a high speed camera (200 Hz) was used to capture 6 forehand strokes of badminton from six badminton elite players and six PE major students. The kinematics data were converted to 15-point of biological motion data including drop, smash and clear shots to both left and right side of the court. Experiment 1: 25 badminton experts and 33 PE major students were recruited to view 144 biological motion clips of the preparatory phase of badminton shots and to identify where the shuttlecock landed. The results showed certain invariant information could be used for both groups, but the percentage of accuracy was low. Furthermore, experts group had better performance in predicting the landing position of the shots, and the depth was more accurately identified than the left-and-right direction. Experiment 2: 12 performers viewed 72 biological motion clips of their complete badminton shots and identified which ones were performed by themselves. The results showed that the performers were unable to identify their own movement and PE group tended to misidentify themselves to be the elites. In conclusion, biological motion can provide invariant information of performance without personal characteristics. The information invariants were provided with the specific mode and affordance also played a role in detecting it.