Tendonitis is the inflammation of a tendon–the tissues that connect muscle to bone. Patellar tendonitis, then, is an injury that affects the tendon connecting your kneecap (patella) and your shinbone.

The knees are the strongest joint in the entire human body. They have to support most of your body weight, and they also provide your overall mobility.

Knee pain is quite common, particularly as we age. This is especially the case with people who have engaged in activities that put extra stress on the knees, such as construction work, athletics, warehouse jobs, and delivery jobs.

There’s no question that knees get a lot of use: walking, climbing stairs, squatting, kneeling, running, and even sitting and standing. And if you play sports, work out, or dance, you can add things like jumping, pivoting, juking, and sprinting to the list.