The patellar tendon, an extension of the quadriceps tendon, joins the kneecap to the shin bone (or tibia). This tendon allows the quadriceps muscle to straighten the leg.
The patellar tendon undergoes a large amount of stress during active leg extension. This is especially true in individuals who put extra strain on the knee joint through activities that involve jumping movements. With repeated strain, micro-tears occur in the tendon that results in inflammation and pain. This is known medically as patellar tendonitis or jumper's knee.
