This is called the tibial tubercle. These main muscle sources are responsible for the movement of the patella. If one set of muscles is not working properly, this will result in pain of the patella since the muscles help the patella glide smoothly over the femur and tibia bone. Other important units of the knee include cartilage, ligaments, and tendons. The cartilage plays a key role in patellofemoral syndrome.
Cartilage is a layer of smooth, soft, tissue.
It acts as a second skin to the endpoints of the femur and tibia bones. This also lines the underside of the kneecap. Since the cartilage is soft, it allows the bones to rub against each other and glide correctly. This soft tissue also acts as a shock or stress absorber. Thus, less pain for the patella.