Functions and Parts of Knee

Sportspeople and athletes are often recommended to take proper care of their knees. Do you know why? That’s because the knee is one of the largest and the most critical joints responsible for bearing the maximum load of our body. A healthy knee joint aids in everyday mobility, thus helping us perform daily tasks efficiently.

A proper understanding of the various parts of the knee and lower leg can go a long way in making us aware of its importance, thereby making us take better care of it. Let’s get a detailed understanding of the various parts of the knee joint.

Structure of the Knee Joint

As one of the most complex joints in our body, the knee joint is made up of the following structures:

1. Bones

2. Ligaments

3. Tendons

4. Cartilage

1.  Bones

knee bones illustration, Credit: Pixabay

There are four major bones that make up the parts of the knee and lower leg. They are:

1. The femur (thigh bone) – it is the longest and heaviest bone responsible for bearing your weight and imparting stability.

2. Tibia (shin bone) – one of the bigger lower leg bones, that runs from the knee till the ankle. It supports the bodyweight along with other bones.

3. Patella (knee cap) – it is a triangular bone that moves as the knee bends. It lies between Tibia and Femur. Parts of the kneecap help in knee flexion.

4. Fibula – it is a thin, lower leg bone that resides on the side of your leg. It acts as an attachment for muscles of the hamstring and forms the ankle joint.

2.  Ligaments

knee ligaments, Credit: Pixabay

Ligaments hold your knee joint together. They include:

1. An anterior cruciate ligament (ACL) – ACL attaches the femur and the tibia. It is present in the knee depth. It functions to stabilize all the rotational motions at the knee during activities like pivoting and cutting.

2. A posterior cruciate ligament (PCL) – It is present behind the knee and attaches femur and the tibia. It prevents the shinbone from a deep backward motion. It runs the risk of being torn due to a force on the shinbone.

3. Medial collateral ligament (MCL) – it attaches the middle side of the thigh bone to the shin bone. It prevents deep inward motion of the leg, keeps the knee stable, and helps in the knee’s rotation movements.

4. Lateral collateral ligament (LCL) – it connects the lateral side of the tibia to that of the femur. It prevents the deep sideways movement of your knee.

Thus, all the knee ligaments help in regulating the sideways as well as forward and backward movements of the knee.

3.  Tendons

knee-tendon model, Credit: Pixabay

Tendon is a thick band that connects muscles to the bones. There are two types of tendons:

1. The kneecap tendon connects the kneecap to the shinbone.

2. Quadriceps tendon, that attaches the kneecap to the thigh bone.

Any injury caused to the tendons will make it difficult for you to straighten your knee.

4.  Cartilage

Knee joint illustration, Credit: Pixabay

Your knee relies on the two knee cartilages to function optimally. These are:

1. Fibrocartilage – It stabilizes your knee joints and lies as a cushion between the surfaces of weight-bearing knee bones.

2. Articular cartilage – it coats the knee bone endings so as to facilitate a fluid joint movement. It does this by providing a smooth surface.

The primary function of cartilage is to facilitate easy joint movement. They are responsible for absorbing shock, thus enabling joints to function smoothly.

What are some common knee conditions?

Man experiencing knee pain, Credit: Pixabay

All the above-mentioned parts of the knee are crucial for the proper functioning of your knee.

Injury or trauma caused to any of these parts result in the development of one or the other knee conditions. Parts of the knee pain are related to an injury in one or more parts of your knee.

1. Knee osteoarthritis

2. ACL or PCL strain

3. Patellar tendonitis

4. Rheumatoid arthritis

1.  Knee Osteoarthritis

It is caused due to aging and wearing of the ligaments. Stiffness, knee pain, and swelling are its common symptoms.

2.  ACL or PCL Strain

Any strain or tear in the anterior or posterior ligaments results in knee instability issues. They require medical attention, and in some cases, surgery.

3.  Patellar Tendonitis

When the tendon that connects the kneecap to the shinbone inflames, it results in knee pain. Those who engage in excessive physical exercises like jumping or running are at a higher risk of developing this knee condition.

4.  Rheumatoid Arthritis

It is an autoimmune condition that can cause severe joint damage. It can affect any joint apart from the knee.

Most of the knee injuries that result in knee pain are caused due to trauma or a fall or twist. Excessive running or jumping can also lead to various knee conditions. A greater understanding of your knee’s anatomy will help you realize its importance in your day-to-day functioning.