Acute lumbar sprains are more common in clinical practice, and these patients are often office workers, people who are inactive for a long time or people who do not like outdoor sports. Suddenly, during prolonged outdoor activities or physical exercise, there is a sudden onset of lumbar pain, which can be acute, or acute lumbar pain can occur the next day. The pain is often characterized by diffuse lumbar pain, such as difficulty in turning when lying in bed, difficulty in bending when in a standing position, such as squatting down to pick up something, but it is also difficult to describe the specific pain site when standing up. During physical examination, some patients, for example, the pressure pain of the lumbar spinous process, Thomas sign, and straight leg raising test are not very obvious. For this group of patients, in order to exclude other problems, X-ray, lumbar MRI and CT can be done for further definite diagnosis.