The remarkable human knee is one of the most complex and important joints in the human body. It is built to simultaneously embody the attributes of strength and flexibility and is put to near constant use to facilitate the performance of a myriad of actions. Your knee has to be sturdy enough to support the impact of your upper body weight while walking or running, yet flexible enough for you to fold yourself into the lotus position for a meditation session for example. The knee joint is mostly made up of components like bone, muscle, ligaments, tendons, cartilage… and each of the component parts of the knee serves a distinct function. The bones of the knee joint provide support, the surrounding muscles furnish the human with the ability to control his/her movements, the ligaments and tendons within the knee joint provide stability, and the cartilage provides cushioning to absorb the shock from the constant pounding associated with daily movement and exercise. When healthy, the components of the knee work together so that we can walk, run, jump, and change direction instinctively. As a matter of fact, the knee works so well when healthy, that many of us do not fully appreciate its importance until something goes awry. I can say that with confidence because I for one certainly didn’t appreciate the benefit of having two perfectly functional knees until I injured one of them.
Knee support is provided by the bones
Ligaments and tendons stabilize the knee joint
ACL: Anterior cruciate ligament
PCL: Posterior cruciate ligament
LCL: Lateral collateral ligament
MCL: Medial collateral ligament
- The ACL resists excessive twisting of the knee and keeps the tibia from sliding too far forward under the femur when a human being in motion comes to an abrupt stop.
- The PCL keeps the femur from sliding too far forward over the tibia.
- The MCL functions to prevent the knee joint from buckling inwards due to an impact on the outside of the knee.
- The LCL functions to prevent the knee joint from collapsing outwards due to sudden impact to the inside of the knee.
- The patellar tendon and quadriceps tendon are both connected to the kneecap and are crucial for controlled bending and extension of the leg.
You’re probably correctly thinking – “Whoa that is a lot of different ligaments and tendons in the same knee that are each tasked with a unique set of functions… and how the heck does the knee work so perfectly without any of those ligaments getting tangled up with each other?” The answer to that questions is that the magic of nature has found a way to ensure that these function specific ligaments and tendons work together to make the working whole far greater than the sum of the parts. Even more amazing is to think that the knee in its finished form wasn’t built in a utilitarian sense per se with nails, hammers, and screws, but rather it slowly developed as you grew up in accord with a developmental program that was embedded in you the moment you dad’s sperm partnered with your mother’s ovum to form you.
Although all these ligaments are important for proper knee function, it is possible to live life without some of them. In other words a torn knee ligament as an isolated injury might make life difficult and perhaps painful, but it certainly will not kill you. Many people live their lives with no ACL and manage to function just fine. As a matter of fact, Dejuan Blair doesn’t have an ACL in either knee but he managed to play basketball at the highest level for many years. Having said that, I would like to emphasize here that Dejuan is an outlier. For most people, playing a demanding sport like professional basketball with no ACLs would mean frequent and painful knee buckling episodes served with a side order of very nasty falls. For this reason, it is highly recommend to fix any torn knee ligaments or tendons in an effort to restore maximum stability to the knee.
The natural cushion of the knee: meniscus
The human body is a truly remarkable feat of engineering. You won’t find anything else on this planet that is as effective and versatile when it comes to the performance of physical and mental tasks. Even some of its constituent parts that aren’t considered as “sexy” in popular culture such as the human knee are still marvels to behold and study. Think about it for a second… how did you and I as fertilized eggs in our mother’s respective wombs know that we’d need a knee someday and how did we go about growing it in the exact right spot? Puzzling right? Yeah I know… I feel the same way at times. So the next time you catch yourself on the verge of falling into a depressive state, stop and remind yourself of how awesome the body you have been carrying around for X number of years is. Lord knows we all need to heed that sort of advice more often. Till next time my friends, take care of yourselves and each other.
This article is an excerpt from “In Kneed of Repair… Getting through ACL reconstruction”. A comprehensive interactive eBook designed to guide you through ACL reconstruction and recovery. You can buy the full iBook for iPad or Macintosh on the Apple iBookstore.
Without Wax
Oyolu B.C. Ph.D.
chubaoyolu.org
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