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Pain When I Bend My Knee: What Could Be Wrong?


For many of us, daily activities involve a lot of bending, from picking up a child to tying our shoes. So when we experience sudden pain in our knees when performing these simple tasks, it can suck.

Many people suffer from this type of pain and at times, we begin to question what type of knee pain are we dealing with.

In this blog post, we will discuss the possible causes of pain when bending the knee and what you can do about it. We’ll also provide tips for preventing pain from occurring in the first place.

Anatomy of the knee

The knee joint is a complex structure that allows for a wide range of motion. It’s made up of three bones: the femur (thighbone), the tibia (shinbone), and the patella (kneecap). These bones are connected by a network of ligaments, connective tissue, muscles, and tendons.

In addition, the knee also contains a small amount of fluid, which helps to cushion the joint and reduce friction.

It is held together by four main ligaments: the medial collateral ligament (MCL), the lateral collateral ligament (LCL), the anterior cruciate ligament (ACL), and the posterior cruciate ligament (PCL).

The ACL runs through the center of the knee and prevents the femur from sliding forward on the tibia.

The PCL runs through the center of the knee and prevents the tibia from sliding backward on the femur. 

The MCL is located on the inside of the knee and helps to stabilize the joint by preventing excessive inward motion. The LCL is located on the outside of the knee and helps to prevent excessive outward motion.

The anatomy doesn’t stop there! The knee is also surrounded by different muscle groups.

The quadriceps muscle group attaches from the front of the thigh bone to below the front of your knee and helps to straighten the leg.

The hamstring muscle group attaches to the back of the thigh bone and helps to bend the leg.

The popliteus muscle is located behind the knee and helps to rotate the leg.

The gastrocnemius (or calf) muscle group is located on the back of your shin bone and helps to flex the leg (or go on tip toes) at the ankle joint.

The iliotibial (IT) band is a long tendon that runs from the hip down to the shin bone. It helps to stabilize the knee joint and hip joint when walking or running. The IT band also helps with postural control.


Why Do I Feel Pain When I Bend the Knee

When you bend your knee, a small amount of pressure is applied to the inside of the joint, due to the physics of this motion. The pressure is necessary to keep the joint lubricated and prevent the bones from rubbing together.

However, if the pressure becomes too great, it can cause the joint to become irritated, resulting in you experiencing different knee problems.

Meniscal Tear

One of the most common causes of knee pain is a meniscus tear. The meniscus is a C-shaped disc of cartilage that cushions the knee joint.

A meniscus tear is a knee injury that occurs suddenly, such as when the knee is twisted during a fall, or it can develop over a long time due to wear and tear.

Symptoms of a meniscus tear include knee pain, stiffness, swelling, and a popping or clicking sensation.

Baker’s Cyst

When you bend your knee, you may feel a sharp pain behind the knee. This is called a baker’s cyst, also called a popliteal cyst, and it’s a fluid-filled sac that forms near the joint.

It occurs when the fluid that lubricates the knee joint (synovial fluid) leaks out into the surrounding tissue. This can happen due to an injury or overuse of the joint.

The baker’s cyst is usually not serious, but it can be painful and cause stiffness in the joint. 

Muscle Imbalance

Muscle imbalance is another common cause of knee pain. This occurs when the muscles around the knee joint are not in alignment. This can be caused by overuse of certain muscle groups or injury.

Symptoms include knee pain, instability, and difficulty bending the knee joint. Treatment for muscle imbalance includes stretching and strengthening exercises, massage, and physical therapy.

ACL Tear

As you probably know, your ACL is the anterior cruciate ligament. It’s a band of tissue that connects your thighbone to your shinbone and helps to stabilize your knee. When you bend your knee, the ACL becomes lax and puts pressure on the surrounding tissues. But if you bend your knee while twisting, the ACL can tear. This can cause pain, swelling, and instability in the joint.

In most cases, it may even require surgery to repair the damage.

Patellar Tendonitis

Patellar tendonitis, also known as “jumper’s knee,” is a condition that results from repetitive stress on the patellar tendon, which connects the thigh muscle to the shinbone.

Patellar tendonitis is a common injury among athletes who participate in activities that involve jumping and sudden changes in direction, such as basketball, volleyball, and soccer.

The symptoms of patellar tendonitis include pain and tenderness around the kneecap, stiffness, difficulty bending the knee, and weakness in the leg.

Rheumatoid Arthritis

For many people with rheumatoid arthritis, pain is a constant companion. The condition can cause pain in any joint in the body, but the knees are often particularly affected.

There are several reasons why rheumatoid arthritis may cause knee pain. The first is that the condition can cause inflammation in the joints, which can lead to pain and stiffness.

Additionally, this painful condition can damage the cartilage that cushions the knee joint, leading to irritation and swelling.

In some cases, rheumatoid arthritis can also cause changes in the alignment of the knee joint, which can further contribute to severe pain and discomfort.

Hamstring Strains

Hamstring strains are one of the most common injuries in sports. The hamstrings are a group of three muscles that run along the back of the thigh, from the hip to the knee.

These muscles are responsible for bending the knee and extending the hip. Hamstring strains occur when one or more of these muscles are stretched beyond their limit, causing small tears in the muscle tissue.

Hamstring strains can be extremely painful and often require a long period of rest and rehabilitation to heal properly.

Patellofemoral Pain Syndrome

Next is patellofemoral pain syndrome, also known as the runner’s knee. This condition is caused by the repetitive stress of running or other high-impact activities.

It can also be caused by sudden trauma, such as a fall or a car accident. The pain is typically felt around the kneecap, and it may worsen with prolonged activity. 

How to Tell if You Have a Serious Injury

Often, knee pain can be attributed to a minor injury or overuse. However, certain types of knee pain may indicate a more serious condition. For example, pain in the front of the knee may be a sign of patellofemoral syndrome, a condition that affects the cartilage under the kneecap. Similarly, pain in the back of the knee may be indicative of posterior cruciate ligament (PCL) injury.

Here are also a few symptoms you should be mindful of:

– Knee pain that persists for more than a few days

– Knee pain that is accompanied by swelling or redness

– Knee pain that makes it difficult to walk or put weight on your leg

Sharp or shooting knee pain

– Knee pain that seems to be getting worse over time

Short-term and Long-term Treatment Options

Depending on the cause of the pain, there are both short-term and long-term solutions that can provide relief.

  • Physical therapy: A physical therapist will help you strengthen the muscles around the knee, which can take pressure off of the joint and reduce pain. They will also conduct a physical exam to assess the severity of your knee injury.
  • Applying ice packs: An ice pack can reduce swelling and inflammation. Apply it at least for 20 minutes, three times a day.
  • Wearing a knee brace: A knee brace can help to stabilize the joint and protect it from further injury.
  • Resting the joint: Give the knee time to heal, which may mean taking a break from activities that put stress on the joint. If you have a more serious condition, such as an ACL injury, you may need surgery to repair the damage.

Exercises to Alleviate Knee Discomfort

For many people, knee pain is a common occurrence. Whether it’s due to a medical condition or simply from everyday wear and tear, knee pain can make it difficult to perform even the simplest tasks. While there are a variety of treatments available, some people may also benefit from exercises or stretches that can help to alleviate discomfort.

For example, certain medical conditions can cause the knee to become stiff and inflexible. In these cases, gentle stretching exercises may help to improve the joint’s range of motion. Take a look at this video for one such exercise.

For those who experience pain when bending the knee, daily activities such as walking or swimming can help to strengthen the muscles and reduce discomfort. By understanding the cause of knee pain, individuals can find the best course of treatment to help them get back to their regular activities.

One gentle exercise that can help you start to bend your knee pain-free again is the ATG split squat. Watch this video to see how this exercise regresses to fit your current fitness level.

How to Prevent Knee Pain

There are several things you can do to prevent knee pain from occurring in the first place.

First, if you have any health conditions that could contribute to knee pain (e.g., arthritis), be sure to manage those conditions properly and follow your healthcare provider’s recommendations.

Second, keep your joints healthy by exercising regularly and maintaining a healthy weight. This will help reduce the wear and tear on your joints, and lower your risk of developing arthritis or other joint problems.

Finally, wear the right shoes for your feet and activities. This will help reduce stress on your knees and prevent injuries.

If you have any concerns about your risk of developing knee pain, be sure to speak with your healthcare provider, they can give you specific recommendations based on your individual health history and lifestyle factors.

Get Assessed by a Health Care Provider

No one knows your body better than you do. And knee pain is never any fun. Whether it’s a sharp twinge when you move wrong or a dull ache that won’t seem to go away, it can put a damper on your day. Healthcare providers have the training and experience to properly diagnose an injury and recommend the best treatment plan for you.