Electromyography and Motor Control Laboratory

Electromyography and Motor Control Laboratory


Laboratory Head: Dr. Francesco Negro and Dr. Utku Yavuz

The execution of a movement is the result of a complex interaction between populations of neurons in the central nervous system, both at the supraspinal and spinal levels. In the last decades, we have gained a detailed knowledge of the properties of single neurons, but we lack of a more general view of their complex network connections. A better understanding of this circuitry is necessary for the development of optimized rehabilitation strategies.

The mission of the EMG Laboratory is the analysis of populations of motor units in vivo in human to extract information about the synaptic control signals involved in the production of voluntary movements. It includes identifying and redefining the current techniques used in the assessment of motor unit properties and neural drive to the muscles.

 

Laboratory activities

1. Simultaneous recording of populations of motor units using advance techniques

Multi-channel intramuscular and surface EMG recordings are processed with novel algorithms for the identification of a large number of motor units during voluntary contractions.

 

2. Understanding the role of afferent feedback in physiological and pathological tremor

During sustained voluntary contractions, force and acceleration show the presence of involuntary fluctuations, which are referred to as tremor. The precise mechanism of this phenomenon is not known. The aim of our laboratory is to explore the importance of afferent feedback in the generation of involuntary fluctuations of force.

 

3. Identification and characterization of motor unit properties

The goal of this research area is to develop new methods for the estimation of motor unit parameters (twitch force, discharge rate, conduction velocity, synchronization, etc.) in vivo

 

4. Reflex studies

The aim is to use reflex responses as a probe to investigate human spinal cord circuitry. The reflex response of motor unit populations is analyzed by peri-stimulus frequencygram technique which shows the time course of the net input current to a motoneuron around stimulation time.

 

5. Computational models of the neuromuscular system

The human motor control system is extremely complex since it comprises a very large number of elements and interactions. This implies an important limit for the mathematical description of such a system. Our aim is to develop advanced models of the motor control system that can explain its behavior.  

 

6. EMG signal processing and modeling

There is a gap between what is known about the generation of EMG activity, and how much of that information can be extracted from the signal.  Advancement in signal processing and modeling will help to bridge this gap.  Main areas in signal processing are wavelet design, blind source separation, time-frequency representation, pattern recognition and compression. The modeling is focused on finite element approaches to describe the volume conductor.

 

7. Motor unit activity following experimental muscle pain

The research aim is the evaluation of the motor unit properties following stimulation of nociceptive afferents in hand and leg muscles.

 

Representative recent publications

Farina D, Negro F. Accessing the neural drive to muscle and translation to neurorehabilitation technologies. IEEE Rev Biomed Eng. 2012;5:3-14.

Negro F, Farina D. (2012) Factors influencing the estimates of correlation between motor unit activities in humans. PLoS ONE, 2012;7(9):e44894.

Dideriksen JL, Negro F, Enoka RM, Farina D (2012) Motor unit recruitment strategies and muscle properties determine the influence of synaptic noise on force steadiness. J NEUROPHYSIOL, 107(12):3357-69.

Negro F, Farina D (2011) Decorrelation of cortical inputs and motoneuron output. J NEUROPHYSIOL, 106: 2688-97.