American Board of Internal Medicine (ABIM) Certification Practice Exam

What syndrome is indicated by lateral knee pain worsened by walking down an incline?

1. Patellofemoral pain syndrome

2. Iliotibial band syndrome

3. Pes anserine bursitis

4. Knee arthritis

The correct answer is: Iliotibial band syndrome

Lateral knee pain that worsens with activities such as walking down an incline is typically indicative of iliotibial band syndrome. This syndrome arises when the iliotibial band, which runs along the outside of the thigh from the hip to the shin, becomes tight or inflamed. The pain is often experienced on the lateral aspect of the knee and can be exacerbated by activities that involve repetitive knee flexion and extension, particularly downhill walking or running. In this context, walking down an incline increases the dynamic friction between the iliotibial band and the lateral femoral condyle, leading to increased irritation and pain. This is a hallmark symptom of iliotibial band syndrome, making it essential for diagnosis and treatment. Other conditions, such as patellofemoral pain syndrome, pes anserine bursitis, and knee arthritis, present with different pain characteristics or exacerbating factors, allowing clinicians to differentiate them based on the specific activities that worsen the pain or the location of the discomfort.