Identification of common synaptic inputs to motor neurons from the rectified electromyogram

•  Oscillatory drives at the input of a pool of motor neurons are transmitted to the motor neuron output (neural drive to the muscle) in an approximately linear way if these inputs are common to all motor neurons. •  The neural drive to the muscle is transformed in the EMG signal that can be thus used to extract information on the oscillatory inputs to motor neurons. •  The transmission of oscillatory inputs is closer to a linear transmission for the raw or for the rectified EMG depending on the energy of the raw and rectified motor unit action potentials at the input frequency and on the degree of amplitude cancellation. •  Amplitude cancellation negatively influences the effectiveness of EMG rectification in identifying with linear methods oscillatory inputs to motor neurons, so that rectification is preferable over the raw EMG only when the degree of cancellation is low.