Hard masses can be palpated on the body surface but are not shown on ultrasound, mainly because of localized muscle strain or localized chronic aseptic inflammation in the body. In daily life, we often encounter muscle damage on both sides of the waist, or in the neck and shoulder area, and in this case, we may feel a hard lump with fuzzy borders, and it may be painful when pressed, and the pain may even increase when the local muscles move. In this case, the ultrasound shows normal tissue stratification and does not show a mass. If the pain is more severe, we recommend that the patient go to the hospital promptly.