Which part of the body is the patella?

The patella is located directly anterior to the knee joint and is easily palpable on the body surface. When the knee is flexed, the bony, rounded prominence that can be felt is the patella—the largest sesamoid bone in the human body. Together with the femur and tibia, it forms the knee joint.

The patella’s surface and surrounding area are attached by fibrous connective tissue, allowing for a degree of mobility. The patellar ligament passes over its anterior surface and connects to it via this fibrous connective tissue. During knee extension, the patella acts as a lever fulcrum, enhancing mechanical efficiency and reducing the muscular effort required for extension. The posterior surface of the patella forms the patellofemoral articular surface, which articulates with the femoral trochlea. As the knee flexes and extends, the patella glides along the femoral trochlea, facilitating smooth knee motion.

The patella also serves a protective role for the knee joint; injury to the patella may impair full knee extension. In daily life, repetitive activities such as running, jumping, weight-bearing, hiking, or ascending/descending stairs subject the patella to excessive stress. This may lead to wear of the patella’s articular surface and result in chondromalacia patellae, causing anterior knee pain during knee movement.