Piper rhythm in the activation of the gastrocnemius medialis during running

Shifts in EMG spectral power during fatiguing dynamic contractions

“…Several recent studies have used the wavelet analysis developed by von Tscharner to investigate periodic rhythmicity in the EMG signal during repetitive dynamic contractions. This rhythmicity has been referred to as the “Piper rhythm” and typically occurs in a frequency band ranging from 30 to 60 Hz. The theory underlying the Piper rhythm is that it reflects rhythmic fluctuations in central drive that are needed for fine tuning dynamic contractions .…”

Heel-strike in walking: Assessment of potential sources of intra- and inter-subject variability in the activation patterns of muscles stabilizing the knee joint

“…Recent 288 studies have reported a heel-strike adjusted rhythm in the EMG signal at around 40 Hz in both running (Stirling et al, 2011) and walking (Huber et al, 2011). However, the exact pulse frequency differed between subjects, which might have led to an inter-subject EMG variability that contributed to the higher-order PC-vector waveforms.…”

“…Even though EMG signals are highly individual, temporal features of processed EMG 60 signals, such as rhythmicity and timing of muscle activation, are common between individuals (Bizzi et al, 2008;Guidetti et al, 1996;Huber et al, 2011;Hug et al, 2010;Stirling et al, 2011). The application of PCA to EMG signals has enabled extraction of information concerning neuro-muscular processes (Astephen Wilson et al, 2011;Ivanenko et 64 al., 2004), the nature of the movement"s coordination (Cappellini et al, 2006;Klarner et al, 2010;Sadeghi et al, 2000, von Tscharner, 2002von Tscharner and Goepfert, 2003a), and mechanical efficiency .…”

Measuring human locomotor control using EMG and EEG: Current knowledge, limitations and future considerations

“…In fact, oscillatory activity, with frequencies in the range of the ones characteristic for the sensorimotor cortex, can be observed in the EMG enevelope (Maurer, von Tscharner, & Nigg, 2013;Stirling, von Tscharner, Kugler, & Nigg, 2011). As the frequency spectrum of the raw EEG and the EMG envelope cover a similar frequency range, we expect that this approach might more likely yield a meaningful coherence.…”