You may be fascinated to know that there’s a medical name for every part of human anatomy. 

It’s important to learn medical names I think – particularly if you’re dealing with knee injuries or longstanding medical conditions and undergoing medical treatment. 

After all – you want to know what your doctors are talking about when it comes to your own health surely?

This post answers the question “what is the knee cap called?” in great detail, as well as explains the function of the knee joint and its associated anatomical structures. 

You’ll find this helpful if you’re a sportsperson or athlete who experiences knee pain from time to time. 

And/or if you exercise on hard surfaces such as running or jogging on the road and are concerned about the health of your knees. 

It’s important to take care of your knees as they’re essential for mobility, weight-bearing, walking, and running as well as hiking, swimming, and cycling to name a few. 

Healthy knee

Being the largest joint in the human body, the knee is an elaborate system and it’s useful getting familiar with your own knee anatomy.

A physical examination of the knee (if done by yourself ) would perhaps not demonstrate much. All you’d see is a smooth surface and triangular bone protruding from the center of the knee.

This protrusion is what we call the kneecap – which is medically termed the Patella bone (or just ‘Patella). 

It contributes to the movement of the knee bones along with leg muscles and certain types of cartilage.

The Patella (knee cap) sits at the front of the knee right at the bottom of the Femur bone (the thigh bone)

It’s the bit that gets bruised the most when you have a fall, or say when you were a kid and would shave your skin off whilst running in the play area at school (we’ve all been there!)

It partly protects the interior knee joint from damage, but this is certainly not the only function of the Patella bone. 

Due to the triangular shape of the Patella and where it’s, equal to the level of the femoral condyles, it enables a wider extension of the knee when the leg is in use. 

‘Extension’ means when you straighten your leg – you can get it straighter because you’ve got a kneecap to help you. 

The ‘Patella ligament’ is connected to the Patella; so too is the Quadriceps tendon which links to the Quadriceps muscle.  

The Quadriceps muscle is a key player in allowing the range of motion of the knee joint, as well as surrounding cartilage and ligaments which enhance knee movement. 


Joint capsule

Inside of the knee is where things get interesting. The knee is the largest hinge joint in the body, connecting the upper and lower parts of the leg together. 

The upper leg bone (the thigh bone) is called the Femur, and there are two lower leg bones called the Tibia (aka the shin bone) and the Fibula.

Alongside the bony anatomy of the knee is an even more complex system of ligaments, muscles, and cartilage which work together allowing the movement of the knee joint.

There are 4 primary ligaments that make up the knee joint. These are:

  • The anterior cruciate ligament
  • The posterior cruciate ligament
  • The lateral collateral ligament
  • The medial collateral ligament

Try and picture the knee joint as it is – it’s a 360-degree structure when you think about soft tissue anatomy, as are the bones of the knee joint (which are the ends of the bones of the thigh and shin.)

The anterior and posterior ligaments run from front to back and are used in knee stabilization. Whereby the lateral and medial ligaments support the joint from the sides of the knee. 

Tendons on the other hand are connectors between bone and muscle. Bundled in with all these are cartilage and synovial fluid, which promotes free movement between bony structures to prevent friction.

Knee problems

Let’s go into common causes of knee pain now. 

Knees are prone to age-related conditions, such as knee osteoarthritis, which is down to generic wear and tear over the years. 

Arthritis is one of the more common reasons for surgical repair of the knee, to enable the patient to reclaim as full a range of motion as possible while minimizing discomfort. 

Knees also suffer from overuse in sports or endurance events, being frequently seen in younger patients. 

So too can ligaments cause tremendous and sudden knee pain if something goes wrong.

An ACL (anterior cruciate ligament) injury is a complaint seen in athletes and sportsmen and women when a sudden change in direction causes instability and the ligament gives way, leading to a sprain or tear.

Tendonitis is another ailment which again is caused by overstraining the knee – through too much use. 

And let’s not forget fractures of the bony anatomy of the knee joint or patellar subluxation. These too happen on occasion. 

You may notice a pattern here – that common knee complaints are down to overusing or abusing the knees. 

Saying that knees can withstand a lot! But it’s important to know the limits and not exceed them, or else you risk injuring yourself. 


Caring for knees

Everybody is different, and there’s no straightforward yes/no answer to knee care. 

As a guide, I advise you to get interested in knee health first off – particularly if you work out a lot and use your legs for strenuous activities. 

Any activity where the knee bends past its normal range of movement is at risk of causing injury unless properly and incrementally trained

Whether that’s through hyperflexion or hyperextension, the knees can withstand a lot as I said but there is a threshold before something snaps or breaks. 

Injuries to the cruciate ligaments are notoriously painful and debilitating as are injuries to the collateral ligaments. Both of these kinds of injuries can also occur in addition to a meniscal tear.

Similarly, activities where knees are used as a shock absorber, such as jumping from a height or sprint running and suddenly stopping can be particularly inflammatory if overdone.

It takes a split second for an ACL tear to happen or for the Patella to fracture due to a nasty fall yet takes months, even years for recovery to take place.  

And if you have been repeatedly doing certain exercises which are straining your knee joints, consider scaling back now. I’m sure other professionals like an orthopedic surgeon would advise the same.

Perhaps try a lower-intensity sport such as swimming or cycling which are by nature, kinder to the knee ligaments and less likely to cause undue damage. 

If you have any questions on knee health please reach out, I would love to be a resource for you. 

And if you enjoyed reading this post, I think you’d find this one informative too.

About the Author

Hi there! I’m Dr. Keagen Hadley, OTD, OTR/L. Straight out of the University of Mary, I’m all about blending my know-how in knee health, well-being, and medical technology. As a licensed occupational therapy doc, I’m here to translate complex concepts into clear, actionable insights – whether it’s knee care or groundbreaking healthcare tech.

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