Tendons are chords of connective tissue that attach the muscles to the bones.

Quadriceps tendon

In the knee joint, the quadriceps tendon joins the quadriceps muscle and the kneecap, also providing power for extension.

Patellar

The patellar tendon (although it is a ligament in nature, it is often referred to as a tendon) connects the kneecap to the tibia.