If there is a clear history of trauma, there may be activity disorders, local swelling and pain, which need to be ruled out by X-ray examination at the hospital. If there is no clear history of trauma, consider two causes: first, temporary synovitis caused by intense activity, which is a sterile inflammation of the joint space, generally does not require special treatment, rest-based, drink more water, generally 7-10 days can be self-healing. Second, growing pains, can be properly supplemented with calcium. If there is a history of trauma, it is recommended to go to the hospital for examination; no history of trauma can be temporarily rested and observed.