Tendonitis is best described as the inflammation, irritation and swelling of the tendons that connect muscles to bones and joints. The condition can affect any tendon and almost any joint in the human body. The most common areas that tendonitis occurs is in the knees, shoulders, ankles, wrists and elbows. In this article we're going to focus on the three types of tendonitis that affect the knee joint.

Before we take a look at the different types of tendonitis that affect the knee we need to cover some basic knee anatomy. The knee is the connecting joint for three main muscle groups; the hamstrings, the quadriceps and the calf muscle. The hamstring muscles are located on the back of your thigh, the quadriceps muscle is located on the front of your thigh and the calf muscles are located at the back of your lower legs.

The knee joint also comprises of three main tendons. These are the hamstring, quadriceps and patellar (knee cap) tendon. These tendons are some of the largest and strongest in the human body. We will look more closely at these tendons later in the article. For now, all you need to know is that there are three different types of tendonitis associated with the knee, one for each tendon.

Let's take a look at how each of these tendons fit into the knee joint and how to tell if that particular tendon has developed tendonitis.

Quadriceps Tendon

It's very common for the quadriceps tendon to develop tendonitis, especially in professional athletes. The quadriceps tendon runs from the bottom of the quadriceps muscle down the front of the knee underneath the patellar (knee cap). If you have quadriceps tendonitis you will feel the pain directly above your knee cap. In some cases, the pain may extend up the front of the leg. The pain will feel worse when you sit down, or bring your foot up towards your buttocks. This is because the quadriceps tendon and muscle have to stretch. You may also find if you have quadriceps tendonitis that the area where your quadriceps meet your knee cap there might be some redness and swelling.

Hamstring Tendon

Hamstring tendonitis is often misdiagnosed as another form of knee injury. This is because the area that gets inflamed is often quite small (despite the large size of the hamstring tendon) and is close proximity to the back of the knee. The hamstring tendon connects to the knee outside of the back of your knee joint. If you have hamstring tendonitis you will feel the pain either in the tendon on the outside of the knee or on the back of the knee. If you feel the pain in the outside of the knee it's obvious that the pain is coming from the hamstring tendon, but if it's behind the knee it's difficult to tell because the hamstring tendon goes deep into the knee. The pain will be at its worst when you try to straighten your leg out, where the tendon is forced to stretch. You will also feel increased pain when you try to twist your foot or point your toes at your knees. Often the entire back of the knee is swollen, but in its early stages hamstring tendonitis will only swell around the outer area of the hamstring tendon.

Patellar Tendon

The correct name for the knee cap is the patellar. Patellar tendonitis is one of the most common forms of tendonitis and the most common form around the knee joint. The patellar tendon starts behind the patellar and extends down to the tendons in the lower leg. So if you were to look at your knee from the front, the quadriceps tendon enters the knee at the top behind the knee cap and the patellar tendon extends from behind the knee cap down to the lower leg area. When you have patellar tendonitis you will feel the pain just below your knee cap or behind your knee cap. You will probably feel the pain whenever you move your knee, in any direction. Sometimes you may hear a popping or grinding sound as you move your knee around. This is because the area is inflamed and the tendon does not have enough room to move.

So, the important points to note from this article are that there is three types of tendonitis that can affect the knee; quadriceps tendonitis, hamstring tendonitis and patellar tendonitis. These are three separate tendons. If you need any more advice about how to treat tendonitis see the links below. Tendonitis can be treated without seeing a doctor, but first you must accurately diagnose which tendon is affected. The next article I will write will be about treating tendonitis symptoms.