Research Group Weightlifting, Institute for Applied Training Science, Leipzig, Germany.
Division of Training and Movement Sciences, Research Focus Cognition Sciences, University of Potsdam, Potsdam, Germany.
PLoS One. 2021 Jul 19;16(7):e0254705. doi: 10.1371/journal.pone.0254705. eCollection 2021.
This study examined the concurrent validity of an inverse dynamic (force computed from barbell acceleration [reference method]) and a work-energy (force computed from work at the barbell [alternative method]) approach to measure the mean vertical barbell force during the snatch using kinematic data from video analysis. For this purpose, the acceleration phase of the snatch was analyzed in thirty male medal winners of the 2018 weightlifting World Championships (age: 25.2±3.1 years; body mass: 88.9±28.6 kg). Vertical barbell kinematics were measured using a custom-made 2D real-time video analysis software. Agreement between the two computational approaches was assessed using Bland-Altman analysis, Deming regression, and Pearson product-moment correlation. Further, principal component analysis in conjunction with multiple linear regression was used to assess whether individual differences related to the two approaches are due to the waveforms of the acceleration time-series data. Results indicated no mean difference (p > 0.05; d = -0.04) and an extremely large correlation (r = 0.99) between the two approaches. Despite the high agreement, the total error of individual differences was 8.2% (163.0 N). The individual differences can be explained by a multiple linear regression model (R2adj = 0.86) on principal component scores from the principal component analysis of vertical barbell acceleration time-series waveforms. Findings from this study indicate that the individual errors of force measures can be associated with the inverse dynamic approach. This approach uses vertical barbell acceleration data from video analysis that is prone to error. Therefore, it is recommended to use the work-energy approach to compute mean vertical barbell force as this approach did not rely on vertical barbell acceleration.
本研究考察了一种逆向动力学（通过杠铃加速度计算得出的力[参考方法]）和一种工作能量法（通过杠铃上的功计算得出的力[替代方法]）在测量抓举过程中平均杠铃力时的同步有效性，其使用视频分析得到的运动学数据。为此，对 2018 年举重世界锦标赛 30 名男性奖牌获得者的抓举加速阶段进行了分析（年龄：25.2±3.1 岁；体重：88.9±28.6 公斤）。使用定制的 2D 实时视频分析软件测量杠铃的垂直运动学。使用 Bland-Altman 分析、Deming 回归和 Pearson 积矩相关评估两种计算方法之间的一致性。此外，还使用主成分分析结合多元线性回归来评估与两种方法相关的个体差异是否归因于加速度时间序列数据的波形。结果表明，两种方法之间没有平均差异（p>0.05；d=-0.04）且相关性极高（r=0.99）。尽管具有高度一致性，但个体差异的总误差为 8.2%（163.0 N）。个体差异可以通过主成分分析中垂直杠铃加速度时间序列波形的主成分得分的多元线性回归模型（R2adj=0.86）来解释。本研究的结果表明，力测量的个体误差可以与逆向动力学方法相关。该方法使用易出错的视频分析得到的垂直杠铃加速度数据。因此，建议使用工作能量法来计算平均杠铃力，因为该方法不依赖于垂直杠铃加速度。
