Knee Injury Ligaments (Part 3)

When you think of knee injuries in basketball, you probably think of an ACL tear or meniscus tear. While these are common and occur frequently, they aren’t the only types of knee injuries that can sideline a player. Several knee injury ligaments can be just as devastating as a torn ACL or meniscus. Ligaments are tough bands of connective tissue found throughout the body. They give structure and stability to joints by connecting bone to bone. Athletes who play contact sports like basketball are at a higher risk for ligament injuries because of the unnatural movements involved.

Leg Muscles AnatomyKnee Injury Ligament

The quadriceps and the hamstrings support the movements and the stabilization of the knee joint. Quadriceps are composed of four individual muscles on the anterior upper leg. These muscles are the vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris. These muscles fuse, forming the quadriceps tendon. Quadriceps straighten the knee by pulling the patella upon contraction.
Hamstrings are the muscles that attach to the tibia, specifically at the back of the knee. It functions by flexing or bending the knee joint. This muscle group also provides stability on both sides of the knee. It consists of three individual muscles: biceps femoris, semitendinosus, and semimembranosus.


The knee’s stability largely depends on the four major ligaments: the MCL, LCL, ACL, and PCL. Ligaments are rigid but slightly elastic bands of connective tissues that hold two or more bones together. Excessive movements, such as hyperextension or hyperflexion, at the knee joint, are restrained by these ligaments, stabilizing the knee joint and keeping the bones in their correct alignment during movements.

Medial Collateral Ligament (MCL) and Lateral Collateral Ligament (LCL)

The MCL resists excessive forces from the knee’s outer surface or valgus forces. The LCL fights the forces coming from the inner surface of the knee or varus forces. These ligaments are located on the outside of the knee joint and can heal on their own.
Knee Injury Ligament

Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL)

The ACL and the PCL closely interconnect and are commonly termed the central pivot. (Johnson, 2004). ACL is within the center of the knee, where the synovial fluid constantly bathes it. These ligaments form a cross right in the center of the knee joint. If one of these ligaments is injured, the damage can completely disrupt the function of the entire knee joint. An ACL injury may result in degenerative arthritis without timely and appropriate treatment.
The ACL is considered one of the essential structures of the knee. Functioning as the knee’s primary stabilizer, the ACL runs from the thigh bone to the shin bone through the center of the knee, providing stability and reducing stress across the knee. It prevents hyperextension of the knee by restraining the excessive forward movement of the tibia and femur. Working with PCL, the ACL limits the rotational activities of the knee. An unstable knee can occur if one of these ligaments is damaged during foot placement or pivoting. Significant knee injury ligaments involving the ACL usually require extensive surgery and prolonged therapy.

Knee Injury Ligaments


Fibroblasts produce collagen, which is a naturally occurring protein. The three bands of ACL supporting the knee through a full range of motion are mainly composed of type-1 collagen fibers. These fibers provide the tensile strength and elasticity of the ACL.
Researchers believe that the PCL functions as a central axis during knee rotation. The PCL is almost twice as vital as the ACL and more resistant to excessive force damage. In contrast to ACL, the PCL is not frequently injured.
That is the end of Part 3. I will have part 4 up very soon.

Other ACL injuries Articles

I will be putting up the next part over the next few days. If you missed parts 1 to 2, Check the following articles:

If you are interested in knee pain, knee injuries, or ACL injuries, these other posts may interest you:
You can attend the live course called Exercise Rehabilitation of the Knee or instantly download my video presentation on Exercises for Prevention, Rehabilitation, and Overcoming Knee Injuries if you are looking for stuff with more details on Knee Injury Ligaments.
Rick Kaselj, MS
Knee Pain Solved