EMG: What is it?
What is sEMG?
The sEMG is a time-variable voltage distribution present on the skin and generated by the muscle(s) below it.
It provides extensive information about the muscle(s), just like the ECG on the chest provides information about the heart or EEG on the scalp does about the brain. Like ECG and EEG it is detected with electrodes applied to skin. The technique is non-invasive and has no risks.
The number of electrode may range from two to hundreds. When a grid of electrodes is used we obtain a time variable image, that is a movie, like in the case of ECG and EEG. It is not a substitute for needle EMG.
What is sEMG useful for?
Surface EMG is mostly a tool for the assessment of muscle condition, coordination, timing and intensity of activation, muscle fatigue, etc. In some cases it allows to estimate changes of muscle force and of load sharing among muscles.
It is a fundamental tool, for kinesiologists, sport and movement scientists and physiotherapists, to study neuromuscular disorders, physio-pathological limb biomechanics and gait, to plan and monitor preventive interventions, to assess the effectiveness of interventions in sport training, microgravity conditions and evidence-based rehabilitation.
It has applications in ergonomics, sport and rehabilitation medicine, in preventive and occupational medicine, in body-computer interfaces and for the control of external devices, exoskeletons and artificial limbs.