What Is Knee Cap Pain (Anterior Knee Pain)?

Pain at or around the kneecap, also known as patellofemoral pain, occurs when the soft tissues and structures surrounding the patella (kneecap) are irritated or stressed. Even though the kneecap itself is a small bone, it plays a big role in how the knee bends, straightens, and bears weight.

Most people describe this pain as a dull ache or soreness that worsens with activity, especially activities requiring bending of the knee.

Common Causes of Knee Cap Pain

1. Patellofemoral Pain Syndrome (“Runner’s Knee”)

This condition is one of the most frequent sources of pain around the knee cap. It happens when the kneecap doesn’t move smoothly in its groove as you bend and straighten the knee, leading to irritation and inflammation in the tissues around it.

Typical triggers:

Repetitive movements like running, jumping, and squatting

Sudden increase in exercise intensity

Poor biomechanics or muscle imbalance

2. Overuse and Repetitive Stress

Activities that put constant strain on the knee joint — such as frequent stair climbing, prolonged kneeling, or high-impact exercise — can overload the structures around the kneecap. This can lead to pain over time, even without an injury.

3. Chondromalacia Patella (Cartilage Wear)

Chondromalacia occurs when the cartilage beneath the kneecap softens or begins to wear down. Cartilage normally protects bones from rubbing together; when it deteriorates, friction increases, leading to discomfort and swelling around the kneecap.

4. Muscle Weakness or Imbalance

Strong, balanced muscles — especially the quadriceps, hamstrings, and hip muscles — help stabilize the kneecap. Weakness or imbalance in these muscle groups can cause the kneecap to track incorrectly, increasing stress and pain.

5. Patellar Tendon Strain and Tendonitis

The tendon that connects your kneecap to your shinbone (patellar tendon) can become inflamed after repetitive jumping or sprinting. This condition — called patellar tendonitis — often presents as sharp pain below the kneecap.

Who Is Most Likely to Experience Knee Cap Pain?

Although anyone can develop knee cap pain, certain factors raise the likelihood:

Athletes and runners exposed to repetitive knee motion

Teenagers and young adults with growth-related imbalances

People with flat feet or biomechanical misalignment

Those with weak hip or thigh muscles

Individuals with high training volumes or poor footwear choices

Symptoms to Watch For

Kneecap pain typically shows up as:

A dull ache under or around the kneecap

Pain when walking, squatting, or going up/down stairs

Clicking, popping, or grinding sensations in the knee

Knee discomfort after sitting for long periods

Occasional swelling or tenderness around the patella