Understanding the effect of window length and overlap for assessing sEMG in dynamic fatiguing contractions: A non-linear dimensionality reduction and clustering

The Short-Time Fourier transform (STFT) is a helpful tool to identify muscle fatigue with clinical and sports applications. However, the choice of STFT parameters may affect estimation myoelectrical manifestations fatigue. Here, we determine effect window length overlap selections on frequency slope coefficient variation from EMG spectrum features in fatiguing contractions. We also whether relationship between slopes task failure. Eighty-eight healthy adult men performed one-leg heel-rise until exhaustion. A factorial design 50, 100, 250, 500, 1000 ms 0, 25, 75, 90% was used. non-linearly fitted as failure function, followed by dimensionality reduction clustering analysis. elicited five patterns. small produced higher for peak (p < 0.001). contrary found mean median larger frequencies. largest dispersion 50 without using frequency. combination 250 50% reduced both peak, median, frequency, but decreased Therefore, selection during dynamic contractions should be accompanied mechanical measure failure, its adjusted according experiment’s requirements.