Knee Sprain Symptoms: Swelling, Bruising, Popping, or Buckling.

Diagnosing a Knee Sprain


Knee sprain is a common injury among athletes or people who are physically active. If not treated properly or immediately, this may result to chronic pain due to muscle stiffness and rigidity. The purpose of this article is to help you identify knee sprain symptoms, its causes, available treatments, and how knee sprain can be prevented.

What is knee sprain?

A knee sprain occurs when one or more ligaments of the knee are stretched or torn.


What are the causes of knee sprain?

  • Sudden movements that put stress on the knee

Sprains may be caused by unnatural movements of the knee. In some sports, athletes plant their foot and turn quickly at the knee. This may result to knee sprain.

Running and stopping suddenly may cause knee sprain. Sudden changes of direction may also result to a sprain. Jumping and landing hard will also cause a sprain.

Any activity that involves quick or sudden twisting at the knees will result in a sprain. Activities that cause a person to hyperextend the knee can also cause a sprain.

  • Direct strike to knees

Direct hits to the front, back, or sides of the knees will cause knee sprain. Tripping and falling to your knees while they are bent can result to sprain.

Football players often suffer from knee sprain because they are forcefully knocked to the ground during gameplay.

What are common knee sprain symptoms?


  • Pain or tenderness

“Why does my knee hurt?” People who get their knee sprained experience different levels of pain depending on the seriousness of the injury. People with mild sprains experience a dull and throbbing pain. Pain is sharp and constant for severe sprains. In most cases of sprains, the pain subsides when the knee is at rest. However, pain returns when the knee is moved.

  • Knee popping

An individual may hear an audible popping sound, the moment the sprain happens. This could mean that one of the four major knee ligaments was torn at the moment of injury. This may be an indication of a more serious sprain.

  • Knee swelling

Knee sprains are typically accompanied by swelling. The amount of swelling, however, varies. There is more swelling when the sprain is severe or if the injury has been left untreated for a period of time.

  • Knee buckling

A person with a sprained knee may feel a sensation of buckling in the knee when he or she tries to stand, walk, or run.

  • Stiffness or decreased movement

When an individual has a sprain, weakness in the affected knee ligament(s) and swelling may limit his or her movements.

  • Bruising

This can occur with all types of sprains but it is most likely to occur after an anterior cruciate ligament sprain or an ACL sprain. With this type of sprain, the bruise will appear on and around the front of the kneecap.

Four main ligaments in the knee are vulnerable to sprains. There are, therefore, four types of knee sprains.


What are the types of knee sprains?


  • Medial collateral ligament sprain


The medial collateral ligament or MCL is a ligament that supports the knee and is located on the inside of the knee. It runs from the lower inside of the femur or thigh bone to the upper inside of the shin.

When force is applied to the outside of the knee while it is still bent or rotating, this may result in a sprain.

This type of sprain is common among wrestlers, skiers, ice hockey, rugby, football and soccer players because of the bending, twisting, and turning movements involved in these sports.

A knee popping sound or shift in the knee is usually an indication of a tear of the MCL. Knee swelling soon after the injury is also a sign of an MCL tear.


  • Anterior cruciate ligament sprain

Anterior cruciate ligament sprain or ACL sprain is prevalent, especially among female athletes. Experts say this may be primarily due to

certain factors:

  • Anatomy

Men have a larger intercondylar notch (the groove at the bottom of the femur where it meets the knee). The movement of the ACL in women’s bodies is restricted because they have a narrower notch.

Women also have wider hips than men. This affects the female body’s alignment of the knees leaving women more prone to have knees that move inward. This causes certain movements to put pressure on the ACL especially when turning or landing a jump.

  • Biomechanics

There are differences in the way male and female bodies move and react. For example, women are more prone to extend the knee more than normal because their knees tend to be more flexible.

Anterior cruciate ligament (ACL) Diagram)


Men, on the other hand, tend to have stronger muscles in their hips, buttocks, and upper legs. Women tend to exert more force on the knee instead of surrounding muscles when they land a jump or change direction. This makes them more susceptible to knee sprain.

  • Hormones

A study by Dr. Kurt Spindler and his colleagues found that “women are nearly three times more likely to injure their ACL during ovulation than during other times of their menstrual cycle.” They evaluated 65 women over a three-year period to determine menstrual cycle phase at the time of their injuries. To this day, however, the experts still do not know why this is the case.

Most ACL injuries are not contact related. They take place when a person lands from a jump or makes sudden changes in direction while running. This type of injury is common among skiers, basketball, rugby, football, and soccer players.

Knee popping and knee swelling are sprained knee symptoms that typically indicate an ACL sprain.

  • Posterior cruciate ligament sprain

Posterior cruciate ligament (PCL) Diagram)


The posterior cruciate ligament or PCL is located at the back of the knee connecting the thigh bone to the shinbone.

PCL sprains are not common. They usually occur together with other knee injuries such as bone bruises or cartilage and ligament injuries. They are caused by direct impact especially in sports that involve falling with a bent knee, or when the knee is twisted or hyperextended.

PCL sprains are common among skiers, baseball, football, soccer, and rugby players. Knee buckling indicates a PCL sprain in addition to other knee sprain symptoms such as knee swelling and knee popping.

  • Lateral collateral ligament sprain

The lateral collateral ligament or LCL is located outside of the knee. It runs alongside the bottom of the thigh bone to the top of the lower leg. It helps stabilize the knee but it is prone to injury.

LCL sprains are the result of a direct hit to the inner knee, twisting the knee or repetitive movements over a period of time.

Pain, knee popping, knee swelling, and tenderness in or around the knee indicate an LCL sprain. Knee buckling and numbness are also knee sprain symptoms indicative of an LCL sprain.

LCL sprains often happen to skiers, basketball, rugby, football and soccer players.

Sprains can be classified into three grades, depending on the severity of the injury.

What are the grades of knee sprains?

The 3 Grades of a Knee Sprain


  • Grade 1

This sprain is the mildest. There is little damage to the ligament. The ligament is stretched and there may be some minor tearing. This level of strain is uncomfortable but putting weight on the ligament is not impossible. A grade 1 strain heals naturally.

  • Grade 2

This sprain is moderate. It involves tearing of a ligament. A person who suffers from this level of sprain may find it more difficult to put weight on the knee and may prevent him or her from walking.

  • Grade 3

This sprain is severe. It usually involves a complete tearing of a ligament from the bone. A person suffering from this level of sprain may find it almost impossible to put weight on the knee. This level of sprain typically requires surgery.


How to Prevent Knee Sprains

There are steps you can take to prevent knee sprains from occurring:

  1. Warm up and stretch before participating in any athletic activity.
  2. Do exercises that will help strengthen the leg muscles around your knee.
  3. Increase the intensity of your training program gradually. Do not push yourself too hard or too fast.
  4. Wear the appropriate shoes for your sport. They should be good quality shoes that fit comfortably. If you have a problem with foot alignment, ask your doctor about shoe inserts that can help correct the problem.
  5. If you are a football player, ask your athletic trainer or sports medicine doctor about shoe cleats that may help reduce your risk of knee injuries.
  6. If you are a skier, use two-mode release bindings that are properly installed and adjusted. These bindings should be compatible with your boots. Before skiing, always make sure that the binding mechanism is in good working order.


When Should You Consult a Medical Professional?

If you injure your knee, call your doctor immediately to request an evaluation if:

  • The knee becomes very painful or swollen.
  • You cannot put weight on your knee.
  • You feel that your knee will buckle or give out when you try to stand or walk.


What Treatments are Available for Knee Sprain?


1. Your doctor may advise you to do the R.I.C.E. method:

  • Rest

You need to rest the affected knee to minimize further injury or damage.

  • Ice

Apply an ice pack wrapped in a towel to the affected knee in fifteen-minute intervals. You need to pause between each session to avoid damaging your skin. This helps reduce swelling.

  • Compression

Wrap the sprained knee in an elastic bandage to help reduce swelling. Just make sure that the bandage should not be too tight. This will cause pain or cut off blood circulation.

  • Elevate

The sprained knee should be elevated with a soft object such as a pillow. This helps prevent the blood from pooling in the area of the sprain. Elevating the injured knee helps to prevent swelling.

2. Your doctor may prescribe NSAIDs (Non-steroidal anti-inflammatories), such as ibuprofen. These medications help to reduce swelling in the injured knee.

3. Your doctor may refer you to a physical therapist who will create a program for you to help strengthen your knee and restore its flexibility.

4. For severe knee sprains, your doctor may recommend surgery to repair the damaged ligament(s).

Knee sprains are not life-threatening. In fact, minor sprains heal on their own with little treatment. However, if ignored or not treated properly, sprains may lead to complications such as long-term dysfunction.

If you are interested to know more about physical therapy treatments for your sprained knee, you can contact Vigor Physical Therapy & Rehabilitation. We are ready to assist you with any questions or concerns you may have regarding our treatment programs. Call us today to schedule an appointment.