Tendons are bands of connective tissue located at the ends of muscles, where they connect with bone. The musculoskeletal system relies on the strength and integrity of tendons to form sturdy attachments between muscle and bone.
Tendonitis is an inflammation of the tendon. It can be caused by trauma, calcium deposits, or infection. Several different tendons can experience tendonitis symptoms near the knee.
Kneecap Tenderness
Inflammation of the patellar tendon is sometimes referred to as "jumper's knee." It occurs in the tendon that attaches the kneecap, also known as the patella, to the quadriceps, which is the muscle in the front of the thigh. Below the kneecap, the patellar tendon attaches to the shinbone, or tibia.
The patellar tendon is essential to certain movements of the knee, including kicking, jumping and pedaling a bicycle. Athletic pursuits that require a lot of jumping are often associated with patellar tendonitis. Pain and tenderness are commonly localized below the knee, where the tendon meets the kneecap, according to the Mayo Clinic.
Pain That Increases With Activity
Pain associated with tendonitis increases with activity whether the activity is as vigorous as working out, or as mundane as climbing the stairs. Tendonitis pain is often described as a dull ache, according to the Mayo Clinic.
A painful tendon that has become overstretched due to physical activity is referred to as a "strain," while a ligament injury is called a "sprain."
Swelling
Swelling occurs when body draws fluid to an injured area. The presence of excess fluid in the body is called edema. Tendonitis of the knee can cause edema in the front of the knee or just below it.
Iliotibial band syndrome is a form of knee tendonitis that is caused by overuse of the knee. It is common in runners, due to the repetitive flexion and extension involved in their sport. Iliotibial band syndrome can cause edema and subsequent swelling, especially on the lateral side of the knee where the tendon inserts into the shin and thigh bones.
Inability To Straighten The Knee
The quadriceps muscle is responsible for extending, or straightening the knee. The patellar tendon attaches to the quadriceps muscle. Inflammation in the patellar tendon can disrupt the quadriceps' ability to move the knee through its entire range of motion. Similarly, iliotibial band syndrome can cause weakness in the knee extensor muscles and inhibit knee extension.
