The most important difference between fasciitis and myofasciitis is the inconsistent location of onset. Myofasciitis is a series of clinical manifestations in which pathogenic factors invade the muscle fibers of the neck, shoulder, and back, causing injury and resulting in aseptic inflammation and resulting muscle pain and spasm. Myofasciitis can present with widespread pain, soreness, heaviness, numbness, stiffness and limited movement in the local muscle and fascia layers, and muscle tension, with painful points of attachment often at the midpoint of the muscle or muscle belly. In contrast, fasciitis is a sterile inflammation of the fascia where the muscles are attached, and can be distributed throughout the body. These are the main differences between the two.