Knee joint


The human body is made up of a large number of important organs and structures, among them we can find the joints . These are a type of anatomical tissue that makes possible and at the same time facilitates all movements of such mechanical and serves as a union between bones and cartilage, to name a few features. One of the largest joints in the body is the knee and it is of the utmost importance for the human body because, thanks to them, locomotion is made possible.


What is the knee joint?

The knee joint is the point of connection between the tibia , the kneecap and the lower part of the femur . It is the largest joint in the body and a fundamental part of the body to communicate and unite the thigh and the leg .

  • Characteristics of the knee joint
  • Function
  • What is your name
  • Parts of the knee joint
  • Bones
  • Muscles
  • Ligaments
  • Knee joint movements
  • Importance

Characteristics of the knee joint

One of its main characteristics is that the knee joint is made up of two secondary joints, the patellofemoral joint, where the bones are mobilized by means of displacement and gives protection to the knee in the anterior part and the femorotibial joint , where the articular meniscus is located.


Other relevant characteristics that can be observed and found in the knee joint, among them we mention the following:

  • It is considered the largest joint of all those that exist in the human body.
  • It has a great and important stability .
  • It can support the full weight of the body.
  • It has excellent mobility which makes walking possible.
  • It is formed by the juxtaposition of two joints considered as secondary.
  • It is a biaxial joint .
  • It has an important dynamic stability .


The knee joint is one of the most important of the human body because it meets the essential function of allowing perform movements both bending as extension of the lower limbs of the human body. This then implies that this joint has the function of intervening and allowing basic human actions such as walking , running or jumping.

In addition, this joint is the one that serves as a communication or union element so that the leg can be connected correctly with the thigh . It has a biomechanical function with regard to the locomotor system . It is also responsible for supporting the total weight of the body.

What is your name

On some occasions, doctors and specialists tend to refer to the knee joint as the tibio-femoral joint , this because it is made up of the femur and the epiphysis of the tibia which, when joined, give rise to a much more stable joint with increased safety in terms of static.

Parts of the knee joint

The parts in which the knee can be divided are separated into two important groups, these are mentioned below:

Bone components

  • Femur : this is a bone that has a bulging part at its end, which makes it possible for weight to be transmitted to the upper area of ​​the tibia.
  • Tibia : helps support the weight of the human body when articulated with the femur. In it we can find two very important cavities known as glenoids, where the condyles of the femur are located.
  • Patella : it is articulated in the back of the femur and has a cartilage that acts as a shock absorber.

Soft tissue components

  • Joint capsule : it is a type of fibrous covering of the bones that surrounds the knee, forming a closed space. It is in this place where the menisci are found.
  • Synovial membrane : it is a layer that is found covering the joint capsule that goes from the femur to the menisci.
  • Bursae : they are a type of fluid-filled sac that has the function of acting as a type of mattress to protect the bone and tendon.
  • Retinacles : they are a type of structure that makes possible the connection between the patella, menisci, tibia and femur.
  • Menisci : they are two structures located between the tibia and the femur that are composed of cartilage and fiber and that also have great elasticity, allowing the compression forces between the bones to be transmitted.
  • Ligaments : they are responsible for giving stability to the knee and prevent extreme movements in the joint. There are two types of them, intra – articular and extra-articular .


The knee joint is made up of three different types of bones which are:

  • Femur : bone that is located in the thigh , it is the longest bone in the human body and the strongest.
  • Tibia : it is also a fairly long bone, it is thick and also very resistant and helps to produce the movements of the knee and ankle.
  • Patella : it is also known by the name of palette and it is a triangular-shaped bone structure that is formed by an anterior and a posterior face. It participates in the extension of the knee, links the tendon and the quadriceps and also helps in the movements of flexion.


The muscles that are part of the knee are the quadriceps, which is considered the most important muscle. It is made up of four muscular-type bellies and is responsible for assisting in the extension movement of the knee. We can also find the hamstring muscles which are located in the back of the thigh, they are also known by the name of femoral muscles and their main function is to perform the flexion movement, in other words they make it possible for the knee to bend. These muscles are the semitendinosus , the biceps femoris, and the semimembranosus .


The ligaments that are part of the knee joint are as follows:

  • Lateral ligaments: they are responsible for stabilizing the lateral part of the knee. There are two types of lateral ligaments: the internal lateral ligament and the external lateral ligament.
  • Cruciate ligaments: they give security and stability to the anteroposterior part of the knee and there are also two types of them: anterior cruciate ligament and posterior cruciate ligament.

Knee joint movements

The knee joint manages to carry out its movements thanks to the bones , ligaments , menisci and muscles that make it up. It has the ability to perform extension and flexion movements but in addition, it can also perform some rotational movements when the knee is in a flexion position, it is worth mentioning that these movements are quite restricted.

Their movements are also due to the muscles that make up the knee joint and these serve as support so that the joint has the ability to move and support the weight of the body. The movements are also carried out in planes and axes . These plans are:

  • Sagittal plane
  • Frontal plane
  • Transverse plane

These movements are also of the rotational type and occur on a perpendicular line with respect to the plane of movement, this is known as the axis of rotation . The axes are also different and among them we find:

  • Sagittal axis
  • Front axle
  • Vertical axis


The knee joint is one of the most important parts of the human body because thanks to it, it is possible to perform a large number of activities that include fundamental acts for life such as walking , running , jumping or bending over . It is also responsible for supporting the total weight of the body , which gives stability and security to the human being.

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