Brueckner Dennis, Göpfert Beat, Kiss Rainer, Muehlbauer Thomas
Division of Movement and Training Sciences/Biomechanics of Sport, University of Duisburg-Essen, Essen, Germany.
Center of Biomechanics and Biocalorimetry, Department of Biomedical Engineering, University of Basel, Basel, Switzerland.
Gait Posture. 2019 May;70:264-269. doi: 10.1016/j.gaitpost.2019.03.019. Epub 2019 Mar 20.
Previous research showed changes in amplitude- or time-derived measures of electromyographic (EMG) activity with motor learning. However, an analysis of the EMG spectral content (e.g., via wavelet technique) has not been included in these investigations yet.
The aim of this study was to use conventional, amplitude-derived EMG parameters along with modern, wavelet-based time-frequency EMG measures to assess the effects of motor practice on learning a dynamic balance task.
Nineteen young male adults (mean age: 26 ± 6 years) practiced a dynamic balance task for two days. Delayed retention test was performed on the third day. On a behavioral level, the root-mean-square error (RMSE) of the stability platform angle was calculated and used as outcome measure. On a neuromuscular level, EMG data from the tibialis anterior (TA) and the gastrocnemius medialis (GM) muscle were unilaterally recorded and analysed by calculating the integrated EMG (iEMG) and the EMG intensity (via continuous wavelet transforms).
Two days of practice resulted in significantly improved balance performance (i.e., lower RMSE) and TA/GM activation (i.e., reduced iEMG and EMG intensity) that was still present during the retention test on day 3. There was also evidence of practice-related changes in the EMG intensity pattern as indicated by an intensity shift from higher to lower frequency components.
We conclude that motor practice leads to improvements in movement effectiveness as indicated by reduced RMSE and in movement efficiency (i.e., decreased iEMG and EMG intensity, intensity shift). In addition to conventional amplitude-derived EMG parameters, modern, wavelet-based time-frequency EMG measures are appropriate to detect practice-related changes in muscle activation.
先前的研究表明，随着运动学习，肌电图（EMG）活动的幅度或时间衍生指标会发生变化。然而，这些研究尚未包括对EMG频谱内容的分析（例如，通过小波技术）。
本研究的目的是使用传统的、幅度衍生的EMG参数以及基于小波的现代时频EMG测量方法，来评估运动练习对学习动态平衡任务的影响。
19名年轻男性成年人（平均年龄：26±6岁）进行了为期两天的动态平衡任务练习。在第三天进行延迟保留测试。在行为层面，计算稳定平台角度的均方根误差（RMSE）并将其用作结果指标。在神经肌肉层面，单侧记录胫骨前肌（TA）和腓肠肌内侧头（GM）的EMG数据，并通过计算积分肌电图（iEMG）和EMG强度（通过连续小波变换）进行分析。
两天的练习使平衡性能显著提高（即RMSE降低），TA/GM激活也显著降低（即iEMG和EMG强度降低），在第3天的保留测试中仍然存在。还有证据表明，EMG强度模式存在与练习相关的变化，表现为强度从高频成分向低频成分的转移。
我们得出结论，运动练习会导致运动有效性提高，表现为RMSE降低，运动效率提高（即iEMG和EMG强度降低、强度转移）。除了传统的幅度衍生EMG参数外，基于小波的现代时频EMG测量方法也适用于检测与练习相关的肌肉激活变化。
