Tibial tuberosity epiphysitis is an overuse injury to the knee that occurs primarily in the adolescent athletic population. It is particularly prevalent in boys aged 10-15 years and in adolescent athletes aged 8-13 years in girls, usually with a higher incidence in boys. The pathology is based on the convergence of the strong quadriceps muscle group down through the patella to form a single patellar tendon attached to the relatively fragile, immature tibial tuberosity. Continuous and prolonged pulling of the patellar tendon during exercise acts on the developing tibial tuberosity, resulting in pain, tenderness and local swelling at the stopping point. Most cases are unilateral, with the possibility of simultaneous onset on both sides. Pain is common after exercise and is relieved at rest, at night, or is absent. Pain is felt during cycling, running, sprinting, jumping, squatting, etc. The recovery period is mostly 6 to 12 months. In general, this injury is self-limiting and does not require surgical treatment, but a small number of patients with severe OSD, long duration, and even adult patients with symptoms still have the need for surgical treatment. Treatment: I. First aid treatment: 1. apply cold compresses for 10 minutes, repeat several times a day, do not use ice directly on the skin, but wrap a towel; 2. rest and reduce labor intensity; 3. do not use ultrasound to treat the painful area, it may affect the growth of the epiphyseal plate. Second, restorative treatment: In the first stage, stretching training of quadriceps and N cord muscles is performed regularly to reduce the strain of muscle tension on patellar tendon; stretching training cannot be performed in the acute stage. 1, quadriceps stretching training. Stand, support the wall with one hand, bend one knee, pull with one hand to maintain the angle and make the heel towards the hip until you feel a pulling sensation in the anterior thigh muscles for 10~15 seconds, then rest for 10~20 seconds and repeat several times; 2, N cord muscle stretching training. One leg straight ahead on a bench or step, bend the body forward, keep the back leg straight and hook the toes of the front leg toward the body. Keep the front leg straight at the same time, maintain 10~15 seconds, rest 10~15 seconds, repeat several times; 3.Coordination training. Stand on the affected foot alone, keep your hands open for balance, then close your eyes and try to keep your balance; 4. Use knee pads or patellar tendon straps for training; 5. For bicycle riding exercises, you can use a variable speed bike, put the gears in low gear, increase the pedaling frequency, and reduce the single load so that the knee joint can be easily completed.