Children’s thigh root pain must be alert to the following two causes: 1, muscle strain: a history of strenuous exercise, to be considered a limited muscle strain, such as sutures muscle strain and so on. It is recommended to pay attention to rest, avoid strenuous activities, local hot compresses, you can give Yunnan Baiyao aerosol topical, pay attention to rest, generally 3-5 days will be good. 2, hip synovitis: synovitis and the recent cold or vaccination has a correlation, the systemic virus into the blood inside, and then confined to the hip joint, the formation of hip joint effusion, resulting in unilateral lower limbs afraid to land, movement is limited, but sitting or The pain is not obvious when sitting or lying down. It is recommended to see a pediatric orthopedic surgeon to rule out acute bacterial hip osteoarthritis or osteomyelitis. If this is ruled out, take 1-2 weeks of rest at home and use topical Yunnan Baiyao aerosol.