The scientific name given to muscle knots, in general, is myofascial trigger points. It can be described as a condition where spots of tight or tensed muscles are formed. They can form in almost any part of the body, like back, neck, hips, etc. You can get knots in the neck all of a sudden while sleeping, or when you are trying to reach out to a high shelf. These give rise to a sharp pain which tends to aggravate when one tries to move the neck.