Sprained Knee
A knee sprain is a common injury that can be quite disabling. The pain, swelling, and stiffness from a sprained knee can prevent you from doing your daily activities. It may even force you to change your lifestyle. Thankfully, simple measures like home exercises can help relieve your knee pain and increase the range of motion.
You can work on strengthening the knee and reduce recovery time. In this guide, we provide you with an overview of the causes, symptoms, and treatment of knee sprains. We also introduce you to some knee exercises that can help you treat your sprain and prevent future injuries.
Content:
What is a knee sprain?
What are the causes of a sprained knee?
Symptoms of a sprained knee
Diagnosis of a sprained knee
Treatment for knee sprains
Other treatment options for knee sprain
Recovery time
Complications of knee sprain
When to see a doctor
Helping you heal from knee sprain
The knee is one of the largest and strongest joints in the body. It supports the body’s weight and allows us to perform many everyday activities such as sitting, standing, walking, and running. The knee is a complex joint made up of different kinds of structures including bones, muscles, menisci, and ligaments. An injury to any of these structures can result in symptoms.
A knee sprain is a common injury, especially among people who take part in contact sports like football and rugby. A sprained knee can also occur during high-intensity sports like skating and skiing.1 This does not mean that knee sprains cannot occur in non-athletes.
You can also be unlucky to suffer a knee sprain as you go about your normal day-to-day activities. This usually happens because of an unnatural movement, like twisting during a slip and fall. Knee sprains can cause crippling symptoms that make it impossible to do your daily activities, let alone take part in sports. The good news is that you can control your symptoms and recover from a knee sprain with simple measures like home exercises.
At Injurymap, we are committed to helping you live a life free of injuries and pain. With this comprehensive guide, we will help you understand knee sprains and how to prevent them. Please remember, this guide is for general informational purposes only. You should get professional medical care if your symptoms do not improve with rehab exercises and other home treatments.
Looking for a solution to knee sprain? Try the Injurymap exercise app now.
What is a knee sprain?
A knee sprain is an injury to a ligament. A ligament is a sturdy band of tissue that connects the different bones in the knee joint. When one or more ligaments are torn or overstretched, it is called a sprained knee. Four major ligaments support and stabilize the knee.2
- ACL (anterior cruciate ligament)
- PCL (posterior cruciate ligament)
- MCL (medial collateral ligament)
- LCL (lateral collateral ligament)
The severity of the ligament tear in the knee can vary. When a ligament is stretched, leading to tiny tears, it is called a mild knee sprain. People with a mild knee sprain (grade I) can usually continue to bear weight on the leg. A moderate (grade II) sprain means the ligament is partially torn. This can lead to pain and knee instability (a feeling that the knee is going to give out while you’re standing or walking). Severe (grade III) knee sprains occur when the ligament is completely torn, resulting in an unstable joint and inability to bear weight on that leg.2
What are the causes of a sprained knee?
The most common cause of a knee sprain is an unnatural movement during physical activity. That’s why this type of knee injury is common among athletes who play sports that involve contact, jumping, running, and turning. For example, knee sprains are more common in people who play basketball, football, and rugby. Sprained knees can also occur during wrestling, gymnastics, and skiing.
Some of the movements that can cause a sprained knee include:1
- Sudden stops
- Sudden changes in direction
- Twisting or pivoting
- Hyperextension (over-straightening the knee)
- Tackling
Besides unnatural movements, a direct blow to the knee can also cause a knee sprain. For example, the ACL can be sprained by a direct hit to the outside of the knee. A direct impact on the front of the knee, for example during a car crash, can lead to a sprain in the PCL. Falls that cause the lower leg to twist outwards can cause an MCL injury. Knee sprains involving the LCL are uncommon because this ligament is protected by the opposite leg. But, a sharp blow to the inner knee can generate a force that stretches or tears the LCL.2
A poor physical condition, lack of flexibility, and decreased strength in the muscles and ligaments surrounding the knee are risk factors for a knee sprain. You can reduce your risk of knee sprain by using the Injurymap app to make your leg muscles strong and flexible.
Symptoms of a sprained knee
The main symptoms of a sprained knee are pain, swelling, stiffness, and tenderness. Many people hear a popping noise when the injury occurs. There can also be instability of the knee. Some people have trouble bearing weight on that leg when the knee sprain is severe.
The ACL and MCL are the most commonly injured knee ligaments.1 The LCL is rarely sprained on its own. LCL injury is more likely during a severe knee injury that involves multiple ligaments.1 The symptoms of knee sprain can vary depending on the specific ligament involved.2
Symptoms of ACL injury
- A popping sensation at the time of injury
- Significant knee swelling that appears quickly after the injury
- Severe pain
- Discoloration (blue and black knee)
- Instability (buckling or giving out when you stand)
Symptoms of PCL injury
- Mild knee swelling
- Minor difficulty with knee movement
- Mild pain which is often worse with kneeling
- Usually no knee instability
Symptoms of MCL injury
- Pain
- Swelling
- Tenderness on the inner side of the knee
- Buckling toward the outside
Symptoms of LCL injury
- Pain
- Swelling
- Tenderness on the outer side of the knee
- Buckling toward the inside
Diagnosis of a sprained knee
If you have symptoms of a knee sprain, some clues can point to the specific ligament that is injured. For example, if you suffered a direct blow to the outer knee, heard a pop, and developed severe pain and knee swelling within a few hours, it points to an MCL and / or ACL sprain. However, it is important to seek medical advice and not self-diagnose.
Your doctor will diagnose a knee sprain based on your medical history and physical examination. They will test the steadiness of your knee and your ability to bear weight on that side. The doctor will compare the sprained knee to the other side and check for discoloration, deformity, and tenderness.2
If your doctor suspects a severe knee injury, he or she may order imaging studies, such as MRI. This will show if one or more of the knee ligaments are torn.
About the author
Juhi Modi has two decades of experience as a medical writer with varied interests and an enduring passion for health, biology, and science. She uses her educational background in medicine to write science-backed articles for clients around the world.
