5 Causes and How to Treat Them

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Knee buckling is when one or both knees feel weak and give out. It can be accompanied by pain, but not always. If it happens a lot, it could be a sign of an underlying medical problem.

Knee buckling is also referred to as knee instability or weak knees.

Frequent knee buckling also raises your risk of falling and seriously injuring yourself, so it’s important to figure out the underlying cause. Keep reading to learn more about the causes of knee buckling and how to treat them.

Many cases of knee instability are caused by injuries, either from high-impact activities, such as running, or an accident. Common knee injuries include:

• ACL tears
• meniscus tears
• loose bodies (pieces of bone or cartilage floating within the knee)

In addition to instability, knee injuries often cause pain and swelling in the affected knee.

Injury-related knee buckling usually goes away after you treat the underlying injury. Depending on the type of injury, you may need to do physical therapy or have surgery. While you recover, try to avoid putting pressure on your knee whenever possible.

The femoral nerve is one of two major nerves in your lower leg. Femoral neuropathy, which refers to dysfunction of your femoral neve, can cause weakness in your knees, making them more prone to buckling. Other symptoms of femoral nerve neuropathy include:

• pain
• tingling
• burning
• numbness in parts of your thigh or lower leg

Many things can cause femoral neuropathy, including:

• diabetes
• certain medications
• arthritis
• heavy alcohol consumption
• neurological disorders, such as fibromyalgia
• injuries

Treating femoral neuropathy depends on the cause, but it usually involves surgery, pain medication, or lifestyle changes. In many cases, neuropathy isn’t curable, but treatment can help to reduce your symptoms or prevent them from getting worse.

Plica syndrome is caused by inflammation of the medial plica, which is a fold in the middle of the membrane that covers your knee joint. In addition to knee buckling, plica syndrome can also cause:

• clicking sounds in your knee
• pain on the inside of your knee
• pain and tenderness in your kneecap

Most cases of plica syndrome are caused by a knee injury or overusing your knee. Treatment usually involves physical therapy to strengthen the muscles surrounding your knee. You may also need a corticosteroid injection to reduce inflammation. In rare cases, your doctor might suggest surgery to remove or adjust your plica.

Arthritis refers to inflammation in your joints, and it often affects your knees. There are many types of arthritis, but knee buckling is a common symptom of both osteoarthritis and rheumatoid arthritis, which is an autoimmune disease. While rheumatoid arthritis usually affects both knees, you may only have osteoarthritis in one knee.

Both osteoarthritis and rheumatoid arthritis can also cause:

• pain
• stiffness
• a locking or sticking sensation
• a grinding or clicking noise

While there’s no cure for arthritis, several things can help you manage your symptoms, including:

• medications, such as nonsteroidal anti-inflammatory drugs
• corticosteroid injections
• physical therapy
• wearing an assistive device, such as a knee brace

Some people with multiple sclerosis (MS) report having knee buckling as a symptom. MS is a condition that causes your immune system to attack the protective covering of your nerves. While there hasn’t been much research into the relationship between knee buckling and multiple sclerosis, weakness and numbness in your legs are common symptoms of MS. This may make it feel like your knee is buckling.

MS can cause a variety of symptoms that differ from person to person, but other common symptoms include:

• vision loss
• fatigue
• dizziness
• tremors

There’s no cure for MS, but corticosteroid injections can help to reduce nerve inflammation in your legs. Taking muscle relaxants can also help if you have stiffness or frequent spasms in your legs.

Frequent knee buckling may be a sign of an underlying injury or condition, so it’s a good idea to follow up with your doctor. In the meantime, try to rest your knee and apply either a hot or cold compress. You can also wear a knee brace or use a cane to reduce your risk of falling when your knees buckle.

You can also try these leg exercises for weak knees.

Knee buckling can range from a mild annoyance to a serious health hazard. Depending on what’s causing it, you may need physical therapy or surgery. Work with your doctor to figure out what’s causing your knees to buckle and use extra caution when walking up or down stairs.

a common symptom of osteoarthritis

Written by Alyssa Anderson

Medically Reviewed by Poonam Sachdev on December 16, 2021

• What Causes a Trick Knee?
• What Are Treatments for Trick Knee?
• How Can I Prevent a Trick Knee?

A trick knee is a condition where your knee suddenly buckles beneath you. This means that your knee loses the ability to support your weight and gives out. In most cases, knee-buckling is associated with the existence of knee pain and can increase knee pain when it occurs.   

Knee-buckling may be just an extreme case of the larger problem of knee instability — where you feel as though your knee is sliding or shifting on the joint. Both problems can be very uncomfortable and interfere with your daily life.

‌Trick knees and knee-buckling are most often seen in older populations, especially people that have already been diagnosed with knee osteoarthritis. It can also develop after some knee surgeries in people of all ages. 

Ten percent of all adults have felt a knee give way. In the majority of these cases, the buckling included some form of prior knee pain.

Younger people may injure a part of their knee and not realize it. For example, slight tears in the anterior cruciate ligament (ACL) or the meniscus — the cushion of the knee — may heal badly. These situations could also lead to the development of a trick knee. 

In about half of all cases of knee-buckling, the patients also had knee osteoarthritis. This is a type of arthritis where the cartilage in the knee joint has been slowly worn away over time. It’s most common in people ages 50 and older. The underlying causes and pain of osteoarthritis may increase the instability of the knee — leading to a greater chance of buckling.  

Weak quadriceps muscles at the front of your thigh are also common in patients who experience knee-buckling and may be part of the cause of your trick knee.  

Your doctor may recommend a brace to help support your trick knee. Physical therapy can also be helpful for building strength in the muscles around the knee and learning how to correct your posture so your weight is evenly distributed. In some cases, joint replacement surgery — where the surfaces of the knee joint are replaced with plastic — can improve stability as well.

If your knee-buckling is actually caused by an underlying condition — such as a torn ACL or meniscus — your doctor will recommend a treatment that is specific to this underlying condition. This could include surgery or anti-inflammatory medicines. In some cases, joint replacement surgery can improve stability, as well. 

There is a very good chance that you’ll fall when your knee buckles. This can lead to any number of further complications — such as sprains and broken bones. These further problems may require their own — specific — treatments. 

Strengthening the muscles around the knees is important to prevent a trick knee.

The quadriceps (quads) are the most important muscles to work on in order to strengthen the knee. Your quads are located at the front of your thighs and are sometimes referred to as a “natural knee brace.” They are necessary for most everyday activities including:

• Standing up and standing still
• Getting out of your car 
• Biking
• Climbing stairs

By doing exercises to strengthen your quads, you’re helping these muscles support your knee. The more support it has, the less likely it is to buckle. These exercises can also help to manage the symptoms of your osteoarthritis, as well. 

You don’t want to focus only on your quads or your body; you should also work out your hamstrings — at the back of your thighs — and the gluteal muscle of your butt. Squats are a great example of an exercise that works out all three of these muscle groups.

In general, you should try to minimize damage to your knees by choosing exercise like: 

• Low-impact aerobic activities. These include using the elliptical instead of running or choosing to swim instead of playing tennis. 
• Strength training for your lower body. Focus part of your workout routine on your lower body with exercises like leg presses. Don’t do exercises that require leg extension, since these could further damage your knee.
• Stretching. Stretch out your legs in a safe and non-painful way a little bit every day. This will help prevent further knee accidents that could increase your rate of knee buckling.  ‌

You should talk to your doctor or make a plan with your physical therapist before choosing the exercise routine that is right for your knee. You could further damage your knee with the wrong exercises.

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Knee injury: consequences and rehabilitation

Knee injury is one of the most common reasons people seek medical attention. First of all, professional athletes are at risk, as well as rollerbladers and cyclists, skiers, and snowboarders. Sometimes people get a knee injury as a result of a car accident.

For mild knee injuries, it is recommended to reduce physical activity and apply ice compresses. Severe injuries will require surgery and rehabilitation with the participation of a physical therapist. The most common types of knee injuries are: bruise, dislocation, knee fracture, sprain, meniscus tear.

Let’s talk about common injuries and rehabilitation methods.

Patient in physical therapy session

Fracture of the knee

Any bone can be broken in and around the knee, but the most common fracture is the patella, for example as a result of a fall or car accident. People with osteoporosis are at risk of fracture due to reduced bone density.

A displaced fracture may require surgery, but if the bone is in the correct position, it is enough to wear an orthopedic immobilizer (fixator) to keep the knee in the desired position, and also not to load the leg and wait patiently for recovery.

If the injury was caused by jumping and landing on a straight knee, then it is important to take not only an x-ray of the patella, but also a CT scan to make sure that the bones are not displaced, the fracture will not cause complications to the femur and will not lead to arthritis in the future and chronic pain.

Knee dislocation

Falls, contact sports and car accidents are the most common causes of knee dislocation. With it, one or more bones can be displaced from their natural position. A dislocation can damage the blood vessels and nerves around the knee and may require surgery. Displacement of the patella can be very painful, but easily reversible injury – you need to see a doctor to set the patella in place and apply a splint. Subsequently, a set of physiotherapeutic exercises developed by a specialist in a hospital or rehabilitation center is recommended.

Tendon rupture

Tendons are soft tissues that connect muscles to bones. In the event of a knee injury, the tendon of the kneecap is damaged. This injury can be obtained during sports and as a result of accidental falls. The elderly are also at risk.

If a person cannot lift their leg due to a torn tendon, they should see a doctor as soon as possible. You may need to do an x-ray and an MRI. If they confirm the rupture, then surgery will be required, after which a plaster is installed. Recovery can be lengthy and should be supervised by an orthopedic surgeon and a physical therapist.

Injury to the meniscus

The meniscus is a small piece of cartilage that acts as a shock absorber in the joint, so if it is damaged, the knee loses stability. A meniscus injury is characterized by inability to flex and straighten the leg, difficulty going up and down stairs, and a characteristic click can be heard when the knee moves. Athletes and dancers know a lot about meniscus damage – this is one of the most common injuries.

A torn meniscus can be identified using X-ray and MRI. Damage may require arthroscopy or surgery. A torn meniscus may require surgery to remove it. When displaced, the orthopedic doctor sets the meniscus in place and puts a plaster or splint, after which physiotherapy is necessary.

There are also degenerative lesions of the meniscus caused by the aging process. Then the injury can be obtained when performing simple exercises: squats, getting up from your haunches, or even in a dream. Treatment and rehabilitation for degenerative lesions should be discussed with an orthopedic and physical therapist.

Tendinitis

This is an inflammation of the tendon that connects the lower leg and the kneecap. Athletes, especially runners, are most at risk, as the cause of tendinitis is constant overexertion and microtrauma. Tendinitis is characterized by pain when pressing on the ligaments and sharp pain during peak exercise during sports. For treatment, you will first need to give up sports, then relieve inflammation with the help of medications, take a course of therapeutic exercises. In special cases, surgery may be needed to remove diseased tissue.

General symptoms

Pain characteristics and intensity may depend on the type of knee injury. But there are symptoms that you should pay attention to in all cases of injury:

• Swelling of the knee,
• Inability to bend or straighten the knee,
• Cracking in the knee,
• Visible bone deformity,
• Increased temperature in the knee area,
• Difficulty carrying weights,
• Constant aching and non-recurring sharp pain,
• Loss of sensation in the knee area.

When to see a doctor

If your symptoms are as described above and first aid and home care do not help, you should see a doctor.
Emergency care is needed immediately after an injury to prevent complications, and in situations of severe swelling and fever in the knee area, which may be an indicator of infection. This is especially important for people with weak immune systems, children, and people who have had previous knee surgery.

An initial examination can be performed by a general practitioner. To make an accurate diagnosis, it is worth contacting a surgeon and an orthopedist. To determine the nature of the injury, the doctor examines the knee and palpates, revealing pathologies. An x-ray may be needed to assess the nature of the injury. An MRI is needed if there is a suspicion of ligament and meniscal injury. Physiotherapists will ensure an effective rehabilitation process.

Risk factors

Factors that increase the risk of knee injury:

• Overweight. Increases stress on the knee joints even during normal activities such as walking or going up and down stairs. It also increases the risk of developing osteoarthritis by destroying articular cartilage.

• Lack of muscle flexibility. Strong and toned muscles help stabilize and protect joints, while muscle flexibility allows for greater range of motion and thus less risk of meniscus injury.

• Some sports. Alpine skiing, basketball, jogging require more stress on the knees than other sports. If you play these sports, it is worth checking regularly with your doctor.

• Previous injury. Having a previous knee injury increases the chance of getting a new one.

The recovery process

The goal of knee treatment and recovery is to return the person to their level of activity and quality of life as they were before the injury. The prognosis for recovery is always individual and depends on the type of injury, as well as the amount of exercise performed. Depending on the type of damage, rehabilitation can take several weeks or several months.

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knee pain – causes and treatment

Symptoms of knee pain

The symptoms of knee pain depend on its cause and severity. Knee pain is a common problem.

Sudden pain in the knee occurs with too much stress and injury.

There may be weakness in the knees, to the point of feeling that the legs are about to give way.

Depending on the cause of the pain, other symptoms may occur: stiffness, clicking in the knee, stuck knee joint in one position, inability to straighten the leg.

How does knee pain affect us?

Knee pain is more common in older people, in overweight (due to increased stress on the joints) and in sports. The knee joints provide freedom of movement, so knee pain greatly affects our lives. With knee pain, we cannot play sports, it is difficult for us to walk and climb stairs.

Ease the pain

DID YOU KNOW?

The knee joint is made up of three bones, tendons that attach muscles to bones, and ligaments that stabilize and connect bones. In the cavity of the knee joint there are two C-shaped cartilages – the menisci. Their main role is to cushion the joint. A fluid-filled bursa keeps the joint moving smoothly.*

69% of people have experienced knee pain.**

Get rid of pain

*Knee (human anatomy): images, functions, ligaments, muscles. 2016 Knee (Human Anatomy): Images, Functions, Ligaments, Muscles. [ONLINE] available at: http://www.webmd.com/pain-management/knee-pain/picture-of-the-knee. [checked 04/18/2016].
**Global Pain Index 2014: GSK-supported study, full report, p. 47

Why knee pain occurs

Knee pain occurs due to trauma (sprains and tendons, dislocations, torn ligaments or menisci), osteoarthritis, tendonitis (inflammation of the tendons) and bursitis (fluid accumulation in joint capsules) .

Sports injuries

Knee injuries are common among athletes. They often have a ligament tear in the knee joint, accompanied by sudden pain in the knee. Runner’s knee syndrome can occur when the knee joint is overstressed, such as when running, walking, jumping and cycling. It usually manifests itself as pain in the patella and occurs due to excessive exertion, injury, disease of the leg bones or muscle weakness.

Inflammatory processes in the knee joints

Damage to the knees in osteoarthritis develops gradually. If, as a result of problems with the hip or ankle joints, a person’s gait is disturbed, then osteoarthritis leads to deformity of the knee joints. This, in turn, is fraught with injury. Knee injuries, even minor ones, increase the likelihood of such injuries in the future.

Find the source of the pain

Pain in the side of the knee can be caused by a torn ligament or a tear in the meniscus (the layer of cartilage that stabilizes the joint). Pain in the front of the knee is usually due to inflammation of the joint capsule and cartilage problems. Pain in the back of the knee can be caused by osteoarthritis.

Treatment

How to diagnose and treat knee pain depends on the cause of the pain. To determine it, you need to consult a doctor. The doctor will examine your knee, check its mobility, swelling, bruising and local temperature increase. Your doctor may recommend physical therapy and a knee brace to relieve pain, refer you for additional tests (x-rays, MRIs, ultrasounds, or CT scans), show you exercises to strengthen your knee, and prescribe non-steroidal anti-inflammatory drugs (NSAIDs) to relieve pain and treat its causes.