Symptoms of lumbar square muscle strain include low back pain and limitation of activities. 1. Low back pain: patients will experience soreness or swelling in the lower back, and the pain can radiate to the buttocks, and it is easy to recur. Low back pain is aggravated by activity, cold and exertion, and can be relieved by rest or hot compresses. 2. Activity limitation: Due to recurrent lumbar pain, lumbar activity will be limited, which will have some influence on bending and rotating activities. Patients with lumbar muscle strain should develop good living habits, develop good posture and sitting posture, and pay attention to keeping the lumbar area warm. The lumbar muscle function exercise can be carried out to enhance muscle strength and improve the function of lumbar spine. If the pain is severe or recurrent, the patient should go to the hospital for further consultation and treatment to avoid delaying the condition.