The knee is a hinge joint that is responsible for weight-bearing and movement. It consists of bones, meniscus, ligaments, and tendons. The knee is designed to fulfill various amounts of functions, including the following:
- Provide enough stability.
- Helps to lower and raise your body.
- Allows twisting of the leg.
- Makes walking much more efficient.
- Supports the body in an upright position without the need for muscles to function.
A knee sprain injury often happens when a ligament within the knee is stretched or torn. Knee sprain risks are even higher during activities that involve weight-bearing while bending or twisting, such as soccer. Generally, ligaments are bands of fibrous tissue that help hold bones together.
Ligaments support the entire knee and keep the joints and bones in the correct position. The bones they hold in place are your femur, tibia, and patella. Therefore, a knee sprain occurs when one or more ligaments in your knee are suddenly stretched. If the ligament stretches too much, it can tear, which is a very serious injury that typically requires repair of the injured ligament.
Your knee has a total of four ligaments that work in unison to help structure and support the joint, allowing for better movement. Any of the four ligaments can be sprained, in fact, a knee sprain can involve more than one. The following four ligaments are known as:
- Posterior cruciate ligament (PCL) – The PCL crosses through the joint and controls the backward motion of the shin.
- Anterior cruciate ligament (ACL) – The ACL creates a diagonal cross shape in the center of the knee joint.
- Lateral collateral ligament (LCL) – The LCL braces the outside of the knee joint.
- Medial collateral ligament (MCL) – The MCL braces the inside of the knee joint.
In some cases, a serious injury to any of the four knee ligaments can impact the rest of the knee as well. For instance, a torn MCL may also result in a sprained or torn ACL.
Causes & Symptoms of a Knee Sprain
Causes for a sprained knee commonly include a sudden twisting of the knee joint – this may occur when you run, jump, land on a hard surface, or stop or change direction rapidly. Knee sprains often happen during physical activity but can occasionally happen at other times. Certain activities that place pressure on your knee joints and ligaments are the most likely to cause a sprain. Additionally, direct hits to the knee may also cause a sprain.
Sprains may be caused by hits to the front, sides, or back of the knee. This type of sprain can occur with an unexpected tumble or a bump into a metal object, wall, or strong piece of furniture. If you also fall while your knee is bent, for instance, falling down the stairs or slipping on a piece of ice, a knee sprain may occur. In severe cases, car accidents are another situation where grade 3 knee sprains occur, as your legs are overly bent while driving or riding in a vehicle.
Knee sprains are graded on a severity scale from 1 to 3, as described below:
Grade 1 knee sprain
Grade 1 knee sprains involve only a small amount of stretching or fraying of the ligament’s fibers. The person may experience mild swelling, pain, or bruising, but can still put weight onto the affected leg. Grade 1 knee sprains require the least amount of time to fully recover.
Grade 2 knee sprain
A grade 2 knee sprain means that the injured ligament is partially torn. If weight is added to the affected leg, the knee may feel unstable and painful.
Grade 3 knee sprain
The most severe grade under the severity classification of a knee sprain, a grade 3 sprain involves a complete tear of a ligament. In some cases, the ligament may separate from the bone. Swelling and bruising may be severe and it may be difficult or impossible to put weight on the affected leg.
If you sprain your knee, you will immediately feel a sharp pain. Oftentimes, a knee sprain will be associated with a popping sound that you will be able to hear or feel. Depending on the severity of the sprain, the pain can be difficult to manage that you will struggle to walk or place weight on the affected leg. After the initial sprain, certain symptoms include the following:
- Pain in the knee joint.
- Swelling or bruising.
- An area of tenderness over the torn ligament.
- Giving out when trying to walk or place any weight on the leg.
- Stiffness and/or reduced movement.
Who gets a Knee Sprain?
Anyone can sustain a knee sprain, but there are several other risk factors that can increase the likelihood of a knee sprain occurring. The following risk factors include:
- Sports – Knee sprains are common in athletes who engage in fast-paced sports, such as soccer, football, basketball, lacrosse, or field hockey. For example, a soccer player might sprain a knee by stopping suddenly or changing direction rapidly with only one foot planted, and a football player might sprain a knee when his foot is planted and another player falls into the knee.
- Prior injury – Having previously sprained a knee ligament increases the chance of a re-injury.
- Improper footwear – An athlete’s shoes should be suited to the athlete’s biomechanics and appropriate for the sport. Inappropriate footwear can put more pressure on the knee joint and / or put the athlete at risk for accidents.
- Cutting and contact sports – For instance, soccer, football, women’s basketball players have a higher chance of experiencing knee sprains.
- Unexpected exertion – People who increase their training intensity level of athletic competition too quickly may increase their risk of knee sprains.
How Does a Knee Sprain Affect You? How Serious is it?
Knee sprains typically do not have many complications that are associated with this type of injury. However, some serious conditions can accompany a grade 3 classification of a sprained knee, such as the following below:
- Joint deformity and destruction
- Permanent or chronic pain
- Absenteeism from work or school
Recommended Treatment & Rehabilitation for a Knee Sprain
Overall, the knee is a complex joint structure and diagnosis can be difficult to progress. A doctor who suspects a knee sprain will want to rule out other possible causes of pain, such as a meniscal tear or tendon injury. Common aspects of a knee sprain diagnosis often include:
A thorough physical examination is an important part of the diagnostic for a sprained knee. Your doctor will begin by evaluating all your knee’s ligaments. During this time, your ability to relax is important to getting a more accurate assessment of the ligament’s status.
Your doctor will want to know how the knee injury occurred, what symptoms you have experienced, and if you have sustained previous injuries. Your doctor may also ask about your symptoms, such as if certain movements cause pain or weakness, or if certain positions or movements relieve the pain.
Medical imaging such as an X-ray or Magnetic Resonance Imaging (MRI), allows visualization of the anatomical structures inside of the knee in order to gauge the severity of the ligament injury. Imaging tests also help determine if other structures in the knee have been damaged. For instance, a patient may have a knee sprain as well as a broken bone, injured cartilage, and / or meniscus tear.
A physiotherapist will develop a personalized rehabilitation program for your knee injury – some general treatment techniques may include:
Your physiotherapist will design a program to address your pain that includes applying ice to the affected knee. They may also recommend modifying some activities that cause pain. Your physiotherapist will use and teach you pain-management techniques to help reduce or eliminate the need for medication.
Depending on your condition, your physiotherapist or healthcare providers may recommend braces, walking aids, wraps, or tape. A cane, walker, or crutches can help reduce your knee pain and improve your ability to walk regularly. Your physiotherapist may recommend that you use these walking aids for a short period of time. He or she may also recommend a brace to stabilize your knee during the initial recovery phase. Wrapping your knee to reduce swelling can also be recommended.
If the mobility of your knee is limited, it can cause increased stress on your knee. Lack of movement in your hip, foot, or ankle also may be forcing your knee to work at a disadvantage. Your physiotherapist may teach you stretching techniques to decrease tension and help restore the normal motion of your joints.
Your physiotherapist may treat your sprained knee by applying hands-on treatments to gently move your muscles and joints. These techniques help to restore and improve proper motion. They also may be used to guide your joints into a less stressful movement pattern.
Strengthening the muscles around your knees and hips will ease the stress on your knees. These exercises help correct problems with alignment and muscle balance around your knees. The following exercise examples include:
Lie on your back with one leg fully extended. Next, with your other leg, wrap your hands around your thigh and slowly straighten your knee until you feel a stretch in the back of your thigh. Try getting the bottom of your foot to face the ceiling. Hold this stretch for 20 seconds, then repeat 3 times a day.
Face the wall, standing about 2 feet away, and place your hands against the wall. Step forward with one foot and keep the knee bent slightly. Next, keep both heels on the ground, while leaning your hips towards the wall. Keep your back leg straight to stretch your calf muscle. Finally, hold this stretch for 20 seconds, then repeat 3 times a day.
Begin by standing with your heels about 6 inches away from a wall and your feet about a foot apart. Your back and buttock should be pressed against the wall. Slowly slide your hips down the wall until your knees are bent at roughly a 45-degree angle. Hold that position for about 5 seconds, and then slowly slide back up to the starting position. Repeat this motion 10-15 times for 2-3 sets a day.
Alternative & Homeopathic Treatment for a Knee Sprain
Most cases of knee sprains can be treated without the need for surgery. Some of these homeopathic treatments include:
Rest, icing, compression, and elevation may be advised to help reduce the initial symptoms of runner’s knee. This protocol will be particularly important if the symptoms are manifesting for the first time.
Non-steroidal anti-inflammatory drugs (NSAIDs)
Over-the-counter or prescribed anti-inflammatory medications can help reduce inflammation and swelling due to anterior knee pain.
Wearing shoe inserts may benefit a subset of individuals with abnormal foot structure or movement patterns while running.
Ginger or turmeric
Both herbed are known for their anti-inflammatory properties. Moreover, some studies have found them to be comparable in effectiveness to ibuprofen, a commonly used NSAID.