Chida Kenta, Inami Takayuki, Yamaguchi Shota, Nishioka Takuya, Yoshida Yasumasa, Kohtake Naohiko
Graduate School of System Design and Management, Keio University, Yokohama, Japan.
Institute of Physical Education, Keio University, Yokohama, Japan.
Front Sports Act Living. 2024 Feb 14;6:1335272. doi: 10.3389/fspor.2024.1335272. eCollection 2024.
The fencing lunge (lunge), characterized by minimal body rotation, offers a movement well-suited for 2D video analysis. However, to the best of our knowledge, the validity of 2D video analysis for fencing has not been verified. This study aimed to validate 2D video analysis by comparing lower limb joints (hip, knee, and ankle joints) angles during lunge using both 2D video analysis and 3D motion analysis methods.
Twenty-two male fencers performed lunge trials that were simultaneously recorded using eight motion capture cameras (Qualisys Miqus M1) and two digital video cameras (Sony AX-450 and AX450a).
The 2D video analysis results exhibited an extremely large correlation in knee joint angles of the front and rear legs in the sagittal with those from 3D motion analysis ( = 0.93-0.99). However, while a robust correlation was found between the ankle joint angles of the front and rear legs ( = 0.82-0.84), a large bias was also observed (-5.23° to -21.31°). Conversely, for the hip joints of the rear leg, a moderate correlation ( = 0.31) and a large bias (-10.89°) were identified.
The results of this study will contribute to the development of coaching using 2D video analysis in competition settings because such analysis can be a useful alternative to 3D motion analysis when measuring the knee joint angle of the front leg and rear leg in the sagittal plane. However, for the ankle joint angle, further research on the optimal shooting position and height of the digital video camera is needed, whereas for the hip joint angle, 3D motion analysis is recommended at this time.
击剑弓步（冲刺）动作的特点是身体旋转极小，为二维视频分析提供了一个非常适合的动作。然而，据我们所知，二维视频分析在击剑中的有效性尚未得到验证。本研究旨在通过比较二维视频分析和三维运动分析方法在弓步过程中下肢关节（髋关节、膝关节和踝关节）的角度，来验证二维视频分析的有效性。
22名男性击剑运动员进行了弓步试验，同时使用8台动作捕捉相机（Qualisys Miqus M1）和2台数码摄像机（索尼AX - 450和AX450a）进行记录。
二维视频分析结果显示，矢状面中前后腿膝关节角度与三维运动分析结果具有极高的相关性（= 0.93 - 0.99）。然而，虽然前后腿踝关节角度之间发现了较强的相关性（= 0.82 - 0.84），但也观察到了较大的偏差（-5.23°至-21.31°）。相反，对于后腿髋关节，发现相关性中等（= 0.31）且偏差较大（-10.89°）。
本研究结果将有助于在比赛环境中使用二维视频分析进行教练指导的发展，因为在测量矢状面中前后腿膝关节角度时，这种分析可以作为三维运动分析的有用替代方法。然而，对于踝关节角度，需要进一步研究数码摄像机的最佳拍摄位置和高度，而对于髋关节角度，目前建议使用三维运动分析。
