The medical term for the muscle knot is myofascial trigger points.
Muscle knots are abnormal areas within the muscle, which cause pain or discomfort. Knots are formed when a muscle spasms and is continually “on”, no muscle is meant to do this, they are supposed to cycle on and off. After some period of time, a knot is formed, which is usually uncomfortable and painful. Massage therapy is a very helpful treatment to work out these muscle knots.
You get it by poor body mechanics. It’s just how we carry ourselves every day. Sometimes it can be injuries. But almost all of us are leaning over something all day at work, or looking down at a computer screen, holding a phone to our ear all the time, sitting and sleeping in awkward positions. When most people get stressed, frustrated or mad, they tend to bunch up their shoulders and hold them up around their ears.
To prevent the muscle knots, try to adjust your equipment so it’s easier on the body, raise the computer screen or lower the office chair so you can look more straight on. Get a head set for your phone and a body pillow to sleep with at night. Concentrate on holding your head back over your shoulders when you walk and sit so your neck muscles don’t get strained from the weight of your head pulling on them.