Knee Injuries: Causes & Prevention

I get boatload of questions about knees, and—oddly enough—I am fascinated with knees! I spent my career as a soccer player protecting my own knees, and because knee injuries are so common, I’ve dedicated my career as a doc to learning everything I can about them and specifically how to heal from knee injuries as well as how to prevent knee injuries.

How knee injuries occur and more importantly how to prevent them, or—in the very least—help you determine if you are at risk for knee injury and reduce your risk of knee injury....
 
Essentially, within your knee, you have FOUR major ligaments:

• 2 cruciate ligaments that are within your knee joint capsule (ACL & PCL), and
• 2 collateral ligaments, that are on the sides of your knee (MCL & LCL).

 
CAUSES OF KNEE INJURIES
Knee injuries are not always the result of a major impact, such as traumatic impacts during sports or auto accidents. The ligaments in your knees (as well as the meniscus) could easily become injured during every day actions, such as stepping off the curb, while hiking or walking your dog.

Your knees may be at risk for injury

There are 3 key factors that put you at great risk for knee injury:
 

1. If you have poor quality ligament fibers. This is mainly due to inadequate nutrition, where ligament fibers are simply not strong enough to withstand even the slightest amount of force (even that of your own body weight).
2. If you have a misalignment of the bones that make up your knee joint (femur, tibia, fibula) and/or if you have any type of muscle imbalance or postural imbalance​, where your knee joint is simply not tracking properly.
3. If there is a miscommunication in your nervous system ​that causes faulty balance or proprioception, it leads you to have poor biomechanics and move in unordinary ways that your body is not meant to move.

 
CRUCIATE LIGAMENTS
So let's discuss the two cruciate ligaments first, (as a side note, cruciate means cross-shaped, as is the case with the two ligaments within your knee joint: they form a cross, overlapping each other, and attach from the femur to tibia.
 
A very easy way to remember the names of your ligaments is based on their location within your knee joint: your ACL is more towards the front, while your PCL is more towards the back.
 
Nevertheless, to dive deeper into how they work and the purpose of your knee ligaments, we can look at what they are doing to stabilize your knees.
 
The easiest way to remember their FUNCTION is based on the movement of your tibia (the main bone in your lower leg), because they are named after the motion of the tibia they are PREVENTING. Therefore, we’ll use your tibia as a reference point, and how the ligaments prevent excessive motion of your tibia as it relates to your femur.
 
“Your ACL is more towards the FRONT of your knee and it prevents the tibia from moving too far FORWARD, while the PCL is more towards the BACK and it prevents the tibia from moving too far BACKWARDS.”
 
“Ligaments are thick, strong bands of tissue that connect the ends of bones together to form a joint. Ligaments also stabilize and strengthen the joint.”

ANTERIOR CRUCIATE LIGAMENT (ACL)

ACL
The most commonly injured ligament in the knee is the Anterior Cruciate Ligament.
 
Again, your ACL is within your knee joint and it forms a cross with the PCL, and is more towards the front part of your knee.

ACL FUNCTION
The main function of your ACL is preventing your tibia (shin bone) from traveling too far forward under your femur (thigh bone). Your ACL prevents forward motion of your lower leg (tibia). When your lower leg goes too far forward, it strains the ACL and causes ACL injures.
 
ACL INJURY - Your ACL can be injured through:

1. High intensity activities or during sports where you get a direct tackle.
2. Planting your foot then twisting or changing directions rapidly could injure your ACL. Like if you're running, for example, and you twist your body fast you could injure your ACL.
3. Another way that you can get an ACL injury would be if you had a big muscle imbalance between your quadriceps and your hamstrings. Your quadriceps are on the front of your thigh and they help to extend your knee straight. Your hamstrings are on the back of your thigh and they help to bend your knee. Many people with a big muscle mass imbalance their quads and hamstrings and this isn't good because if your quadriceps are too strong they could really send your knee out into hyper extension like that while you're running and then that could potentially lead to an injury over time. So if you have a muscle imbalance between your quadriceps and hamstrings, you want to correct that to reduce your risk of knee injury.
4. And finally, if you have something called genu-recto-vatum or hyper extended knees, where your knees are hyper extended in a standing position, that repeat stress on the ACL ligament could lead to an ACL injury over time, because when your knees are really hyper extended, you're stressing your ACL.​

POSTERIOR CRUCIATE LIGAMENT (PCL)

PCL
So let's discuss the PCL; PCL stands for your Posterior Cruciate Ligament. Now, PCL injuries are much less commonly than the ACL injuries, partially because they go unrecognized, but more because your PCL is stronger, with 2,000 times the tensile strength as your ACL. 
 
Although it is larger and stronger than the ACL, the PCL can be torn. PCL tears make up less than 20% of injuries to knee ligaments. Injuries that tear the PCL often damage some of the other ligaments or cartilage in the knee, as well.
 
PCL FUNCTION
Again, the main function of your PCL is preventing your tibia from traveling too far backwards under your femur.
 
PCL INJURY
If that's the primary function of the PCL, then the main way this ligament becomes injured is through traumatic incidences where the tibia is forcefully pushed too far backwards.  
 
PCL injuries are often due to a blow to the knee while it's bent. Common causes include falling on your knee while it's bent or striking the knee against the dashboard during an auto accident. With a car accident, as an example, say you're driving and you have your knees bent like while sitting and you have a head-on collision. When your knees collide with the dashboard, the tibia is forced backwards with the impact.
 
Because the PCL is one of the strongest ligaments in your knee, it takes a traumatic incident or impact to injure it. That said, it could be injured if any of the above mentioned factors are at play: poor nutrition, joint misalignment, or improper biomechanics. All of those play a role. If you plant your foot and quickly change directions, as football and soccer athletes do during games, that is another way your PCL could be injured.

​COLLATERAL LIGAMENTS (on the sides of your knee)
Now let's talk about the two collateral ligaments. Your MCL and LCL are on the middle (medial) and outside (lateral) portions of your knee, respectively.

MEDIAL COLLATERAL LIGAMENT (MCL)

MCL
So let's talk about the one injured more commonly, which is the MCL or your medial collateral ligament, on the inner part of your knee.
 
MCL FUNCTION
Your MCL prevents your knee from going inward.
 
MCL INJURY
This ligament can also be injured in a traumatic incident like a football tackle. Say someone tackles you and collides with the outer portion of your knee or thigh, and you're knee is forcefully pushed inward, that can cause an MCL injury.
 
Another example is if you have a mal-position, with a genu-valgum where your knees are constantly in a knock-kneed position. This could lead to constant ligament strain and over time cause injury. 
 
If you have a muscle imbalance, where your gluteus maximus muscle is too weak, this can cause internal rotation of your femur. Your gluteus maximus is the main hip external rotator. Because your gluteus maximus externally rotates your hip, when it is weak your knees will always be turned inward and this can lead to your MCL being under constant stress, and can lead to your MCL becoming injured over time due to overuse.

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LATERAL COLLATERAL LIGAMENT (LCL)

LCL
Now let's look at your LCL, which is not injured as frequently as the MCL. Your LCL is on the outside (lateral) portion of your knee.
 
LCL FUNCTION
Your LCL prevents your knee from going outward.
 
LCL INJURY
Your LCL could be injured—once again—through a traumatic incident. In this case, the LCL would be put under the most strain with a football tackle to the inner portion of your knees, where your knee is forcefully pushed outward.
 
In addition, your LCL will experience strain with an “athletic move” (or a sharp change of direction) after planting your foot, and rotating. This type of rapid change of direction across your body would strain the outside of your knee and LCL on the outside leg.
 
Like the MCL, the LCL can be injured or at risk if you have a mal-positioning known as a genu-varum, where your knees are constantly in a bowlegged position. If you're bowlegged, there is a greater amount of stress on your LCL.

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​If you currently have a knee injury or have had a knee injury in the past, let us know. We can help you heal your knee injury and get you back “in the game.”
 
If you're struggling to recover from a knee injury (before or after surgery) we can help you.
If you play sports and want to prevent knee injuries, definitely call us and set up a visit. We can perform simple tests to determine if you are at risk for knee injury and help you set a strong foundation to prevent any knee injury to your ACL, PCL, MCL, LCL and meniscus.
 
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Functional Health & Chiropractic Care
14677 Midway Rd. Ste 101, Addison, TX 75001
DrLiziePilicy.com
 
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Dr. Lizie Pilicy is a chiropractor in Addison, TX who has been helping people from the Addison and North Dallas area heal, get well and stay well through chiropractic care... to help people in Dallas improve their health. Affordable Chiropractic care in Dallas, TX is available!
 
Call today to schedule an appointment in our Addison, TX chiropractic office located at:
 
Functional Health & Chiropractic Care
14677 Midway Rd, Ste 101 Addison, TX 75001
Phone: 978-846-1964
http://www.DrLiziePilicy.com
 
Healing and preventing Knee Ligament Injury (ACL, PCL, MCL, & LCL).