While visibly obvious, fatigue is hard to quantify. Electromyography (EMG) measures conduction along nerves in a particular muscle group--as muscle fibers fatigue, EMG signals shift from high to low.

During the test, a needle probe is inserted into your muscle to measure its electrical activity. The EMG turns the electrical activity into sounds, graphs, or numbers for your doctor to interpret.

As an aside on this point, here’s a graph from a 2013 Brazilian ... stimulation to determine how much of the fatigue was in the muscle, and EMG to get an estimate of the strength of the signal ...

2 The aim of the present study was to investigate the effect of a 2000-m rowing time-trial on indices of quadriceps muscle fatigue. Methods Eight competitive ... and normalised root mean square of the ...

The investigators used electromyography (EMG) to measure muscle electrical activity. In particular, they objectively measured ...

and the EMG amplitude of ST increased by 10% in late swing phase across pre-test and post-test. Conclusions The reduction in maximum combined hip flexion and knee extension angle indicated that the ...

sensitive and practical measurement tool for muscle fatigue" and demonstrate "the potential of IMUs in substituting EMG sensors toward providing a reliable tool for long-term use in industrial ...

The investigators used electromyography (EMG) to measure muscle electrical activity. In particular, they objectively measured muscle fatigue through changes in the frequency of the EMG signal.