Pain and tenderness on the inside of the knee, approximately 2 to 3 inches below the joint, are symptoms of pes anserine bursitis of the knee. The pes anserine bursa is a small lubricating sac located between the shinbone (tibia) and three tendons of the hamstrings muscle at the inside of the knee. Because the three tendons splay out on the front of the shinbone and look like the foot of a goose, pes anserine bursitis is also known as goosefoot bursitis.

Bursitis, an inflammation of a bursa, usually develops as the result of overuse or constant friction and stress on the bursa. Pes anserine bursitis is common in athletes, particularly runners. People with osteoarthritis of the knee are also susceptible.

Several factors can contribute to the development of pes anserine bursitis, including:

• Incorrect training techniques, such as neglecting to stretch, doing excessive hill running and sudden increases in mileage
• Tight hamstring muscles
• Obesity
• An out-turning of the knee or lower leg
• Osteoarthritis in the knee
• Medial meniscus tear

The symptoms of pes anserine bursitis include:

• Pain slowly developing on the inside of the knee and/or in the center of the shinbone, approximately 2 to 3 inches below the knee joint.
• Pain increasing with exercise or climbing stairs
• Symptoms may mimic those of a stress fracture, so an X-ray is usually required for diagnosis

Athletes with pes anserine bursitis should take steps to modify their workout program so that the inflammation does not recur. Other treatments include:

• Rest - Discontinue the activity or substitute a different activity until the bursitis clears up.
• Ice - Apply ice at regular intervals three or four times a day for 20 minutes at a time.
• Anti-inflammatory medication - Aspirin, nonsteroids, or acetaminophen may ease the pain and reduce the inflammation.
• Injection - Your doctor may inject a solution of anesthetic and steroid into the bursa, which often provides prompt relief.