Have you recently hurt your knee? You may be worried that the injury is a torn ACL. Where does ACL pain come from, and where is ACL pain located? Those are great questions and ones that this article will answer.

In this article, we will dive into the knee joint anatomy, the most common knee injuries, how they are diagnosed, and treatment options for you to discern what your condition may be and how to proceed. For a definitive answer, please meet with your healthcare provider.

Knee Joint Anatomy

The knee joint is comprised of various components. The bones involved in the knee joint are the femur (thigh bone), tibia (shin bone), and patella (knee cap), which can be found in the middle of the knee and protect the major ligaments. There are four main ligaments comprised of two groups: the cruciate ligaments and the collateral ligaments. The cruciate ligaments are:

  • anterior cruciate ligament (ACL)
  • posterior cruciate ligament (PCL)

The collateral ligaments are:

  • Medial collateral ligament (MCL) 
  • Lateral collateral ligament (LCL)

All four of these knee ligaments work to keep the knee stable, but they are not the only structures inside of the knee. One other structure that is pertinent to mention is the meniscus, which is a cartilage that cushions the end of either long bone to ensure rubbing does not occur and provides shock absorption during physical activities.

If you are having knee pain, one of these structures may have been injured.

Knee Injuries

If you are having knee pain, it could be due to either an accident during your workout routine or maybe a sports-related injury. Below is a list of the most common sports injuries that can occur to the knee joint.

  • ACL injuries: if you notice an audible popping sound during a non-contact injury, you may have had one of the most common injuries to the knee joint. These injuries occur during sudden changes of movement or a direct hit to the knee that causes the knee to buckle. 
  • MCL injuries: if you are hit on the outside of the knee and your knee buckles inward, you may have had an MCL injury. An MCL tear can occur alone or in combination with the tear of another structure of the knee. 
  • Meniscus injuries: if you have deep internal pain that occurs as a result of twisting or notice clicking that could have developed over a long period, you may have a torn meniscus. Like the other injuries on this list, a torn meniscus could occur due to a direct blow to the knee or be a non-contact injury as a result of knee ligament injuries in contact sports.

There are multiple grades of knee ligament tears. 

  • Grade 1: a sprained knee, where the ligament(s) were stretched further than normal. 
  • Grade 2: a partial tear to the ligament(s)
  • Grade 3: a complete tear to the ligament(s)

Knee injuries or ligament tears are serious, and if you believe you have one of the above, you should seek immediate medical attention from your healthcare provider.


Where is ACL pain located?

ACL pain is felt deep in the center of the knee. The ACL forms an “X” in the inner knee with the PCL, and together they prevent extraneous forward and backward movement of the knee joint. If injured, you will feel discomfort and a “giving out” feeling directly underneath your kneecap. 

Accurate Diagnosis

If you believe you have a knee injury, it is very important to go to the doctor to determine the extent of the injury. When you arrive, you can expect a few routine things to occur:

  • A physical examination can include a lachman test if you have a damaged ACL.
  • Discussion of your medical history to make sure the provider has a grasp on how the injury occurred and what other injuries you have had in the past.
  • Imaging of the joint can include magnetic resonance imaging (MRI), a CT scan, or an x-ray, depending on which structures are involved with your injured leg.

Once your primary provider understands your situation and the severity of your injury, they will either refer you to an orthopedic specialist or one of the other sports medicine specialists to ensure you receive the best treatment for your condition.

Treatment Options

Treatment options for knee injuries and injuries overall can be broken into two main categories: nonsurgical treatment and surgical treatment.

Types of typical nonsurgical or conservative treatment are:

  • RICE, which is a typical recommendation, stands for rest, ice, compression, and elevation
  • Physical therapy involves a physical therapist who is a movement and rehabilitation specialist who can help you increase your range of motion and return to your prior level of physical activity
  • Wearing a knee brace, which can help provide stability and protect joints from further damage

Non-surgical treatment is typically for those with mild injuries who do not require more intensive medical intervention to achieve a full recovery. Surgical intervention is warranted for those who have injured the body in a way that cannot heal naturally.

Orthopedic surgeons are medical professionals who perform surgeries on the knee joint. The type of surgery required and recovery time will vary depending on the injury. Presently, surgeries are mainly done arthroscopically, which is much less invasive and only involves a small incision and a tiny camera to view and “fix” the damaged tissue. The move from “open” to arthroscopic surgeries has made the healing process much more patient-friendly.

To ensure you are following the correct course of action, talk to a medical professional about the treatment plan that is right for you.


Risk Factors

While it is impossible to predict who will hurt their knee, it is possible to look objectively at risk factors that can contribute to these injuries. Below are common risk factors for knee and ACL injuries:

  • Female athletes are at a higher risk of their anatomy and joint laxity
  • Athletes who play contact sports are at a higher risk of incurring a knee injury, such as football, basketball, or soccer players.
  • Athletes who are overweight are at a higher risk of injuring their ACL.

While the literature shows these are the normal risk factors, it is not certain you or anyone else will have a knee injury. Even if you don’t fit into any of the above categories, you could still injure parts of the knee. The truth is, no one fully understands why these injuries occur, so do your best to maintain a high activity level and keep in shape to minimize your chances.


If you have pain or instability deep within the center of your knee, you may have a torn anterior cruciate ligament. But it is impossible to know without the proper evaluation. Whether you have a mild injury or an injury that requires the eyes of an orthopedic surgeon, your best option is to consult with your primary care physician as soon as possible, so you receive the proper treatment in a timely fashion.

To minimize the likelihood of knee injuries, maintain a high level of cardiovascular fitness and focus on exercises that strengthen the muscles and tendons of your knee joint. These precautions will help you better prevent and recover from any knee joint-related injuries.

For more informative posts on knee injuries and how to recover, take a look at my blog here.

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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