We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.

Medical News Today only shows you brands and products that we stand behind.

Our team thoroughly researches and evaluates the recommendations we make on our site. To establish that the product manufacturers addressed safety and efficacy standards, we:
  • Evaluate ingredients and composition: Do they have the potential to cause harm?
  • Fact-check all health claims: Do they align with the current body of scientific evidence?
  • Assess the brand: Does it operate with integrity and adhere to industry best practices?
We do the research so you can find trusted products for your health and wellness.
Was this helpful?

A hyperextended knee is a type of injury to the knee that happens when the knee bends too far backward. It can cause symptoms such as moderate to severe pain, swelling, weakness, instability, and more.

A hyperextended knee often occurs after high-impact events, such as landing hard after a jump or stopping short when running. Due to the nature of this injury, athletes are most at risk, particularly those involved in contact or extreme sports.

When this injury occurs, it is not uncommon for a person to notice swelling, be in moderate to extreme pain, and have soft tissue damage in or around the knee.

In this article, we take a close look at the symptoms of a hyperextended knee, how to treat one, and how long it takes for a hyperextended knee to heal.

Fast facts on hyperextended knee:

  • Female athletes are at higher risk than their male counterparts for a hyperextended knee injury.
  • Doctors and physical therapists can often easily treat this injury by recommending the rest, ice, compression, and elevation (RICE) method.
  • In more extreme cases, a person with hyperextended knee may also have damage to the ligaments and other connective tissue in the knee, including the blood vessels and nerves.
Was this helpful?
Hyperextended kneeShare on Pinterest
A hyperextended knee may occur after high-impact events. Symptoms can include swelling, severe knee pain, and visible bruising.

A hyperextended knee is often easy to spot when it happens. A person can often feel the knee bend backward out of line with the leg.

When a hyperextended knee occurs, it is very likely the person will experience the following symptoms:

  • moderate to severe knee pain
  • swelling
  • instability in the knee
  • feeling of weakness in the knee as if it is giving out
  • visible bruising

People will often experience reduced mobility following a hyperextended knee. It is usually difficult to straighten or bend the injured knee. Reduced mobility may be due to one of the following:

  • damaged ligaments
  • swelling
  • weakness in knee

The symptoms will range from mild to severe depending on how far back the knee was bent. The severity of the injury and damage to the surrounding tissues and ligaments affects how much pain and swelling a person will experience.

Share on Pinterest
Using a brace when resting a hyperextended knee injury is recommended.

Treatment for a hyperextended knee depends on how severe the injury is. Often, treatment begins with RICE.

R — rest

Following a hyperextended knee injury, it is a good idea to stop the activity that caused the damage in the first place.

For an athlete, this may mean sitting out a few games. For the average person, rest may mean not walking on the injured leg or using a brace.

During rest, a person may also:

  • receive physical therapy to restore range of motion
  • use pain medication
  • use anti-inflammatory medication

I — ice

Ice is a popular treatment for injuries such as a hyperextended knee, as it helps reduce swelling and relieve some pain.

A person should apply ice to the hyperextended knee for about 15 minutes at a time, multiple times a day. Ice should always be used with a barrier, such as a towel, to prevent damage to the skin.

C — compression

Compression involves wrapping the injured knee with some pressure. Elastic support bands or compression wraps are available for this purpose. Some knee compression wraps can be viewed here.

Compression, in the same way as ice, can help reduce pain and swelling from the injury. It can also provide a little support to the weakened knee.

E — elevation

The injured knee should be elevated whenever possible. The knee should be held above the heart, which is often accomplished by laying down and raising the leg on a pillow or other comfortable platform.

Treatment for severe cases

In more extreme cases, a hyperextended knee will require surgery to fix the ligaments or alignment of the knee.

A torn anterior cruciate ligament (ACL) is the most common complication, but other tendons and structural supports can be damaged. The ACL is a pair of ligaments in the knee.

It is possible that multiple areas of the knee will require surgery to repair.

Recovery time from a knee injury varies. In less severe cases, a person may recover within 2 to 4 weeks from the time of the injury.

During recovery, a person needs to avoid any activity that can make the injury worse. Also, a person should use the RICE method.

If surgery is required, recovery is likely to take much longer. It can take 6 months or more to recover from surgery fully. Though it will take a long time, most people will see a full recovery.

As part of the recovery process, a doctor will likely recommend physical therapy. Even if a person has had surgery, physical recovery is still required to restore muscle strength and range of motion.

Share on Pinterest
Swimming may be recommended to increase strength following a hyperextended knee injury.

There are many exercises that a person can do following a hyperextended knee injury. The goal of the exercises is to improve range of motion and increase strength.

A person should discuss exercise options with their doctor or physical therapist.

Some potential exercises that a person may do include:

  • swimming
  • gentle hamstring stretches
  • stationary bike
  • straight leg raises
  • wall sits
  • lateral step-up
  • quad sets — strengthening the quads (thigh muscles) by contracting, holding and releasing the muscles, placing a rolled towel under the knee for support if lying down

The exercises that a person does while recovering from a hyperextended knee should be gentle to start with and get progressively more challenging as a person’s knee recovers and gets stronger.

People who experience a hyperextended knee injury may see full recovery following their injury.

A person must seek medical attention as soon as possible following the injury and follow all recommended treatment advice for the best chance of full recovery.

It can be difficult for athletes and active people to rest, but it is necessary for the best recovery from a hyperextended knee.

A person can reduce their risk of getting a hyperextended knee through exercise and stretching. It is essential that the muscles surrounding the knees are strong. Also, stretching both before and after exercise, when the muscles are warm, is crucial as well.