Do you know what is Electromyogram, Electromyography or EMG? We have heard of ECG and EEG and we know what are they used for. ECG is also called as EKG, which is the German spelling for Electrocardiogram (ECG). For those who are not familiar with EMG, let us quickly find out what it is and where is it used.
Electromyography or EMG in short, is used for recording the electrical activity produced by Skeletal Muscles. Electromyograph is the instrument used for this and Electromyogram is the record of the activity. There are more than 600 muscles arranged around the human body skeletal framework and inside. We know that these muscles are responsible for the movement of our body. These muscles contract, expand and simulate which create electrical impulses similar to the electrical activity of the heart.
How EMG Works
An EMG provides valuable information regarding disorders of the muscles. During voluntary contraction of the muscles, the electrical signals are produced. Electrodes of Electromyograph are connected to the particulr muscle to be analyzed. These electrodes carry the signals to the recorder which plots them in the form of a graph on paper. One or more small needles (electrodes) are inserted through the skin into the muscles. One may be asked to contract the muscle by lifting or bending for carrying out the test.
But how do the muscles produce electricity? A muscle is made up of many motor units. One such motor unit consists of single branching Neuron from the Spinal Cord to the Muscle Fibers. Thus a rise in Potential Difference is created, which is recorded in the form of Electromyogram. As it is difficult to isolate a single fiber, single Muscle Cells are not usually monitored in an EMG test. EMG records the Electric Impulses from several fibers.
Read more about Electromyography here