Patellar tendonitis is the inflammation of the tendon that contains the patella. This condition is also called Jumper’s Knee, Patellar Tendonitis, Patellar Tendinopathy, or Sinding-Larsen-Johansson disease. This condition is seen most often in children between the ages of 10 and 16 years old. Patellar tendonitis is a cause of aching pain in the lower part of the patella. It is especially found in athletes who jump a lot, such as those involved in basketball and volleyball. However, patellar tendonitis may also be found in those playing ultimate Frisbee, football, tennis, skateboarding and snowboarding. Even kickboxing and jumping rope may predispose a person to develop this. The condition progresses from pain felt during jumping and activity to pain felt 24/7 whenever using the knee at all. Cause It’s the repetitive motion that causes patellar tendonitis. The repeated trauma causes micro-tears in the tendon that aren’t healed if additional tears continue to occur. Treatment and Prevention Patellar tendonitis may need surgical repair if it is in the later stages of progression. Early in the disorder, it’s good to rest from the activity that is causing the problem, ice the area, use a compression bandage, and elevate the leg as much as possible. Strengthening the muscles and tendons that support the knee is highly recommended. One of the most obvious ways to prevent this disorder is to check the shoes that one is wearing before starting sports activity. Are the shoes worn? If so, they should be replaced with ones that support the feet. The use of orthotic arch supports to biomechanically support the foot is also recommended as this will prevent any patellar alignment problems that are more likely to induce the injury. The act of jumping requires strong arches of the foot, thus arch supports are an important part of prevention.