EMG Recruitment & Fatigue Indicators

Superpose size-ordered motor-unit trains and inspect how recruitment, rate coding, and MUAP broadening affect RMS and spectral median.

Chapter 7
EMG
motor units
spectral median

Recruited units

12.000

RMS amplitude

0.049 mV

Median frequency

97.0 Hz

Force index (arbitrary)

297.5

Motor-unit pulse superposition

Interference EMG50 ms RMS envelope

Spectral broadening and median-frequency shift

Current spectrumUnfatigued, same units/seed

Size-principle recruitment

Model scope

24 ordered virtual motor units, derivative-Gaussian MUAPs in illustrative mV, size-ordered recruitment and rate coding. Fatigue stretches MUAPs by 1+1.5f and reduces arbitrary force per unit; no compensatory recruitment is assumed. RMS and median frequency depend on effort, geometry, temperature, and conduction velocity; neither is a standalone diagnostic fatigue measure.

Preparing the simulation…

Conceptual bridges & related modules

EEG Rhythms, Spectra & ERP Averaging
companion · Chapter 7
Compare power-density normalization and physiological confounding of spectral features.