自由式游泳選手軀幹穩定能力之技術分析-高階選手個案研究

Technique analyses of the trunk stability for freestyle swimming athlete: case report of an elite athlete

目的：在競技游泳戰國時代，各游泳強國使用先進科學方法優化訓練。然而，在傳統訓練和缺乏科技環境以模擬真實條件下，導致國內選手對於技術的改善效果受到限制。為找出更精準的動作分析和監測方法，本研究目的是藉由角速度感測器監測游泳選手動作，以作為選手動作穩定性的技術改善。方法：本研究以台灣一位自由式奧運級選手為對象，採用慣性測量單元進行選手身上六個感測點的資料數據收集。在 50 公尺自由式的游泳中，選手動作透角速度感測器測量，獲得資訊並回饋給教練，分析後執行新的穩定性矯正訓練計畫。經過 12 週訓練，讓選手再回到測驗現場測驗，經數據比對前、後測驗的角速度差異以評估改善成效。結果：由角速度結果的判讀，可知選手的 X 軸與 Y 軸經過校正訓練後都較前測穩定，減少 X 軸旋轉的不對稱及 Y 軸的上下晃動 (Y 軸最大改善 60 %)。但是，感測器的結果也顯示，因為矯正訓練，導致 Z 軸發生代償現象，造成後測的左右晃動較前測大 (Z 軸增加 70 %)。結論：本研究顯示受試者脊椎的感測器，有助於分析選手於各三個方向軸線動作的細微變化，介入矯正訓練後，能改善受試者於游泳各階段動作的穩定性，同時感測器的輔助也發現代償的現象，將更有助於未來教練的訓練和調整方向。

 

Purpose: In competitive swimming, teams try their best to use advanced scientific methods to optimize training. However, traditional training lacks the technological environment to simulate the real conditions. Therefore, the improvement of the athletes’ swimming technique is limited. To find out a more accurate movement analysis and technical monitoring method, this study uses the angular velocity sensor to determine the different points of the athletes’ movements during swimming through the sensor device, to improve the stability of the athletes’ movements. Methods: This study took freestyle Olympians as the subjects. The inertial measurement unit was used to collect data on six detection points on the athletes’ bodies, and to analyze the processes of catching water, pushing water, moving arms in the air, and returning to the water. In the 50-meter freestyle swimming, the athletes’ movements were measured through the angular velocity sensor, and the data were collected and fed back to the coach to implement a new training plan. After 12 weeks of corrective training, the athlete returned to the test. The differences in angular velocity between the pre-test and the post-test were compared. Results: Our analysis indicates that, after corrective training, the athletes’ post-test X-axial and Y-axial data are more stable than those from the pre-test which reduces the asymmetry of the X-axis rotation and the up and down shaking of the Y-axis (improving Y-axis 60 %). However, the sensor data results also show that the Z-axial rotation is compensated due to the corrective training, causing the left and right shaking of the post-test to be larger than that of the pre-test (Z-axial 70 % worse). Conclusion: This method proves that the sensor can record information on the athletes’ movements, and then analyze the stability of the athletes’ movements in each stage of swimming. The results also show that the sensors attached to the athletes’ back were helpful to distinguish the subtle changes in the athletes’ movements in each of the three axes. These results could also be of great assistance for coaches to improve their athletes’ postures and future training direction.