Institute of Research and Development, University of Vale do Paraíba, São José dos Campos , SP, Brazil.
J Sports Sci Med. 2007 Oct 1;6(CSSI-2):23-7. eCollection 2007.
IN MARTIAL ARTS AND CONTACT SPORTS, STRIKES ARE OFTEN TRAINED IN TWO DIFFERENT WAYS: with and without impacts. This study aims to compare the electromyographical activity (EMG) of the triceps brachii (TB), biceps brachii (BB) and brachioradialis (BR) muscles during strikes with and without impacts. Eight Yau-Man Kung Fu practitioners participated in the experiment. Each participant performed 5 sequences of 5 consecutive KF Yau-Man palm strikes with no impact intercalated with 5 sequences of 5 repetitions targeting a KF training shield. Surface EMG signals were obtained from the TB, BB, and RB for 3.0 seconds using an eight-channel module with a total amplifier gain of 2000 and sampled at 3500 Hz. The EMG analyses were done in the time (rms) and frequency (wavelet) domains. For the frequency domain, Morlet wavelet power spectra were obtained and an original method was used to quantify statistically significant regions on the power spectra. The results both in the time and frequency domains indicate a higher TB and BR muscle activity for the strikes with impacts. No significant difference was found for the BB in the two different scenarios. In addition, the results show that the wavelet power spectra pattern for the three analysed muscles obtained from the strikes with and without impacts were similar. Key pointsEMG analysis of a sequence of Kung Fu strikes demonstrates higher Triceps Brachii and Brachioradialis muscle activity for strikes with impact than strikes without impact.An original reliable method for quantifying EMG wavelet transform results is presented.EMG wavelet power spectra describe muscle roles during a Kung Fu sequence of strikes.
在武术和搏击运动中，击打通常有两种不同的训练方式：有接触和无接触。本研究旨在比较有接触和无接触击打时肱三头肌（TB）、肱二头肌（BB）和桡侧腕屈肌（BR）的肌电图（EMG）活动。8 名咏春拳练习者参与了实验。每位参与者进行 5 组连续 5 次无接触咏春拳掌击，每组之间插入 5 组连续 5 次击打咏春拳训练盾牌。使用具有总放大器增益为 2000 的 8 通道模块，在 3.0 秒内获得来自 TB、BB 和 RB 的表面 EMG 信号，采样频率为 3500 Hz。EMG 分析在时域（rms）和频域（小波）进行。对于频域，获得了 Morlet 小波功率谱，并使用原始方法对功率谱上的统计显著区域进行量化。时域和频域的结果均表明，有接触击打的 TB 和 BR 肌肉活性更高。在两种不同情况下，BB 没有发现显著差异。此外，结果表明，有接触和无接触击打的三种分析肌肉的小波功率谱模式相似。关键点：咏春拳掌击序列的 EMG 分析表明，有接触击打的 TB 和 BR 肌肉活性高于无接触击打的 TB 和 BR 肌肉活性。提出了一种用于量化 EMG 小波变换结果的可靠原始方法。EMG 小波功率谱描述了在咏春拳掌击序列中肌肉的作用。
