Anatomy of the knee

Ever wonder what’s the largest joint in the body? It is the knee that has the largest joint in the body. The anatomy of the knee is so structured to carry the body weight while providing stability for the lower extremity during weight lifting.
It is a hinge joint that moves by a bend and straight action. It is very different from the shoulder and hip joints which allows different movements. The anatomy of the knee is made up of two joints which allow bend and flex movement and also slight rotation from side to side. These joints are:

1. Tibiofemular joint

It joins the tibia (shinbone) to the femur (thighbone). The femur is the longest bone of the body the tibia being the second-longest.

The knee joint with the femur and the tibia by means of fibrous connective tissues called ligaments.

The four major ligaments of the knees are:

  • medial collateral ligament – located in the inner part of the knee
  • lateral collateral ligament-located at the outer part of the knee
  • anterior cruciate ligament – this cross in the center of the knee restricts forward movement as well as rotating movement.
  • posterior cruciate ligament – it weaves inside the knee joint and restricts backward movement of the tibia.

Enclosing the tibiofemoral and patellofemoral joints is the joint capsule. It provides increased stability to the knee. The prepatellar bursa is located on the front of the knee. this is a fluid-filled sac that serves as a joint cushion and reduces friction with its other parts. The folds in the synovium are called plicae.

2. Anatomy of the knee  – Patellofemoral joint

It joins the patella (kneecap) to the femur. When the knee extends, it slides superiorly up. When the knee flexes, it slides inferiorly down.

The anatomy of the knee that help stabilizes the patellofemoral joints are:

  • lateral femoral condyle – It limits lateral motion during flexion
  • retinacular tissue – situated medially and laterally.

The knee is composed of 4 bones namely:

  1. The femur (thighbone)
  2. Tibia (shinbone)
  3. Fibula (calfbone)
  4. Patella (kneecap)

The anatomy of the knee includes the tibia and fibula which are two bones of the lower leg.

The tibia runs from the knee to the ankle, while the fibula is a long and narrow bone on the lateral side which runs alongside the tibia from the knee to the ankle.

The femur is the longest bone of the body which runs from the hipbone to the knee. It provides support to the entire body. The triangular-shaped bone is the patella which serves protective functions for the knee joint.

The cartilage of the knee

The knee has two types of cartilage, the first is the

1. fibrocartilage – In the middle of the knee is the fibrocartilage called the meniscus. The meniscus is composed of the lateral menisci and medial menisci.

2. articular cartilage – The end of the femur, the top of the tibia, and the back of the patella are covered by the articular cartilage. This cartilage works by reducing friction between the bones during the action.

The muscles that make up the knee are:

Extensors of the knee

  1. quadriceps femoris
  2. rectus femoris
  3. vastus medialis
  4. vastus lateralis
  5. vastus intermedus
  6. tensor fasciae latae

Flexors of the knee

  •  hamstring
  •  biceps femoris
  •  semitendinosus
  •  semimembranosus
  •  popliteus
  •  gracilis
  •  sartorius

Internal Rotators of the knee

  1. semimembranosus
  2. pes anserinus
  3. semitendinosus
  4. gracilis
  5. sartorius

External Rotators

  • biceps femoris

These muscles act at the knee joint by flexing, extending, and rotating movement. The anatomy of the knee is very complicated and when one thing goes wrong the pain can be great and cause a lot of mobility issues in your life. Take care of your knees and don’t take them for granted.

Common Causes of Chronic Knee Pain

chronic knee painWhen chronic knee pain becomes such a burden that it starts having a significant impact on the quality of your day-to-day life, finding relief from the pain becomes a top priority.

Not being able to perform simple everyday tasks because of bad knees is quite frustrating for those suffering from chronic knee pain.

When pain persists over time, that pain becomes classified as “chronic” instead of “acute”.

The reasons for the development of chronic knee pain are many and include excessive tension placed on the knees or disease. The incidence of chronic knee pain becomes higher as we age.

It helps to have a core understanding of what the knee’s structure is in order to comprehend the causes of chronic knee pain.

To put it in terms that most people can understand, the knee is a joint involving a complex system of soft and hard tissues which links the upper and lower parts of the leg in a way that allows it to have a wide range of movement.

If you ever tried walking in a cast you should have a clear appreciation for just how important the knee is, as it has to do all of this while supporting the entire weight of a person.

If any of the elements of this complex system are damaged, a person is likely to suffer from some form of chronic knee pain.

Injuries that Cause Chronic Knee Pain

Because the knees play an essential role in the most basic activity, there is a certain amount of wear and tear on the joint, and overuse of its structures often leads to chronic knee pain.

As an example, if overuse leads the cartilage disc that acts as a buffer between the kneecap and the bone to degrade significantly, there will be chronic knee pain as a result of the friction between them.

In cases where there is a problem with the patella (the round bone we think of as “the knee”), it may be necessary to use a support to effectively sustain its alignment to the femur. Such support can help alleviate chronic knee pain associated with this condition, known as Patellofemoral Syndrome.

Among the usual injuries that can cause problems are ligament injuries and tendinitis, which can be treated through normal means such as rest as anti-inflammatory drugs. Ice can also be used to help alleviate any issue of this sort.

Another common problem would be a meniscus tear, which is a much more serious issue that requires surgical correction.

Those with serious knee pain should see a doctor and get an x-ray to determine the extent of the problem.

Diseases that Cause Chronic Knee Pain

In terms of diseases that lead to chronic knee pain, we have various types of arthritis and gout. In cases of osteoarthritis, there is a problem causing the deterioration of the cartilage in the knee structure.

In contrast to that, there are gout and rheumatoid arthritis which can often lead to pain from the formation of a cyst at the back of the knee. The cyst is formed because of the inflammation in these conditions, which causes fluids to gather.

Issues can also be caused by conditions such as lupus and bursitis. Bursitis is thought to be caused by excessive tension, for example kneeling too often. Lupus, on the other hand, is a disorder of the connective tissue in the knee’s structure that has no clear, known cause.

While anti-inflammatory drugs such as aspirin can be used to treat the symptoms of these disorders, it is highly advisable that a doctor is consulted, especially when the pain persists.

There are many things you can do to prevent chronic knee pain from arising due to an injury, such as:

– Dieting. Because the knee has to support nearly your entire body weight, getting rid of excess fat will be of enormous benefit in easing the stress it has to deal with on a day to day basis.

– Avoid jumping into activities without being prepared. Slowly ease your way into any new exercise routine so your body has time to adapt and protect your joints.

– Good shoes that are comfortable and provide good support will protect your knees when you need to spend extended periods on your feet.


Even though you may feel deprived of a full life because of chronic knee pain, there is no reason you can’t use the information and treatment methods that modern medicine gives us to deal with the issue intelligently and minimize the negative effect knee pain has on your daily life.

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