Knee pain in a 7-year-old girl may be related to trauma as well as abnormal patellar development and physiological factors. 7-year-old girl active after falling down the knee landing may cause soft tissue injury, serious will cause patellar fracture, there will be knee pain, swelling, subcutaneous bruising, limited activities and other symptoms. If there is no obvious trauma history of frequent knee pain, it may be related to abnormal development of the knee joint, such as patellar subluxation. If the patella slides abnormally during knee flexion and extension activities and rubs excessively against the medial and lateral condyles of the femur, pain will occur, and in more severe cases, surgery may be required for correction. If the daytime activity is too large, in the night rest will also appear the phenomenon of physiological pain, after a few days of rest will be able to naturally relieve. 7-year-old girl knee pain, there may also be other reasons, it is recommended to go to the hospital in time, complete the examination to determine the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.