| 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
WORDS: Electromyography, wavelet transform, impact, martial
arts, biomechanics.
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