With knee extension, in which direction does the patella slide?

During knee extension, the patella slides superiorly. This movement occurs as the knee extends from a flexed position to a straightened position. The patella, which is a sesamoid bone situated within the quadriceps tendon, moves due to the action of the quadriceps muscles, primarily the vastus medialis, vastus lateralis, and rectus femoris. As the quadriceps contract to extend the knee, the pull of these muscles causes the patella to glide upward in the femoral groove.

This superior movement is essential for maintaining proper alignment within the knee joint and ensuring efficient and smooth motion during activities such as walking or running. Understanding the biomechanics involved in knee extension is crucial for physical therapy, particularly in assessing knee injuries and developing rehabilitation strategies.