Back of knee pain: Everything you need to know

Have you ever had a persistent discomfort or sudden sharp pain at the back of your knee? If so, you're not the only one. Back of knee pain, or posterior knee pain, is a common issue that can affect people of all ages and activity levels. 

Whether you're an athlete who pushes yourself to the limit or someone who enjoys a pleasant walk, understanding this condition is important for keeping your knee healthy and enhancing your general wellbeing.

What is back of knee pain?

Back of knee pain, or posterior knee pain, is any discomfort or ache you may have in the region behind your knee joint. This pain can be a constant dull ache to a sudden sharp pain, which may increase in severity when moving around. One thing to note is that the pain is not always localised to an exact spot, and sometimes it spreads down to your calf or goes up into your thigh.

The back of your knee is a complicated area that is formed by the meeting of muscles, tendons, ligaments, and blood vessels. Any problem with any one of these can cause pain. In some cases, the pain might be due to an injury to these structures, while in others, it might be because of an underlying condition that affects your knee joint.

Common causes of back of knee pain

Now, let’s discuss the common reasons for back of knee pain. Knowing these could help you recognise what might be causing your pain and direct you to the right treatment.

Baker's cyst (popliteal cyst)

A Baker’s cyst, or popliteal cyst, is a fluid-filled sac that forms behind the knee. It’s usually a consequence of other underlying knee issues, including arthritis or a meniscus tear. When these conditions lead to increased production of synovial fluid, the fluid may extend into the back of your knee and bulge, forming a cyst.

You may feel a Baker’s cyst as a soft swelling at the back of your knee. It can cause a sense of tightness, particularly when the affected leg is completely straightened. Sometimes, a Baker’s cyst can pop, causing severe pain and swelling in your calf.

Posterior cruciate ligament (PCL) injury

The posterior cruciate ligament (PCL) is one of the four primary ligaments that support your knee joint. It helps maintain the stability of your knee joint as it stops your shin bone from moving backwards beyond a certain point in relation to your thigh bone. A PCL injury is usually caused by a direct blow to the front of your knee when it's flexed, such as in a car accident where the knee hits the dashboard.

PCL injuries can range from mild sprains to complete tears. You might hear a popping sound at the time of injury, followed by pain, swelling, and instability in your knee. Walking downstairs or sitting down might become particularly painful.

Meniscus tear

Your meniscus is a C-shaped piece of cartilage that acts as a cushion between your thighbone and shinbone. A meniscus tear can be caused by a sudden twist or rotation of your knee during an activity, or it can be caused by wear and tear over time as you age.

If you have a torn meniscus, you may have pain, stiffness and swelling. You may also hear a popping sound at the time of injury. Some people have a feeling that their knee is stuck, or it locks so they can’t move normally.

Hamstring injuries

Your hamstrings are a group of muscles at the back of your thigh that help you bend your knee. Hamstring injuries are more likely to happen when you’re engaging in activities that involve sudden acceleration and deceleration or quick changes in direction.

A hamstring injury can cause sudden, sharp pain in the back of your thigh that may extend down to the back of your knee. You might also experience swelling, bruising, and weakness in the affected leg.

Deep vein thrombosis (DVT)

Deep vein thrombosis is a condition that develops when a blood clot forms in one of the deep veins of your body, and is most often in the leg. Although DVT may not present symptoms at all, it usually leads to pain and swelling which may be felt at the back of your knee.

DVT is a serious condition that requires immediate medical attention. If the blood clot is not treated, it may break off and travel to the lungs, causing a very dangerous condition known as a pulmonary embolism.

Arthritis

There are different types of arthritis that can cause back of knee pain. Osteoarthritis, the most common form, occurs when the cartilage in your knee joint wears down over time. Rheumatoid arthritis, an autoimmune condition, can also affect your knee joint.

Arthritis often causes pain, stiffness and swelling in the affected joint. Symptoms can be worse in the morning or after periods of inactivity, and in the long run may cause your knee to have limited mobility.

Back of knee pain symptoms

General symptoms of back of knee pain

While symptoms can vary depending on the underlying cause, some common signs of back of knee pain include:

• Pain or discomfort behind the knee, which may be sharp, dull, or aching
• Swelling or a feeling of tightness
• Stiffness, especially after periods of inactivity
• Difficulty fully straightening or bending the knee
• Weakness or instability in the knee
• Clicking, popping, or locking sensations

Symptoms for different back of knee pain causes

Different causes of back of knee pain may present with unique symptoms:

• Baker's cyst: A visible lump behind the knee, which may be painless or cause a feeling of tightness
• PCL injury: Instability when walking downstairs or sitting down, possible swelling and bruising
• Meniscus tear: Sharp pain, especially when twisting or rotating the knee, possible locking of the joint
• Hamstring injuries: Sudden, sharp pain in the back of the thigh, possibly extending to the knee, with potential bruising
• DVT: Swelling, warmth, and tenderness in the affected leg, sometimes accompanied by redness
• Arthritis: Chronic pain and stiffness, often worse in the morning or after inactivity

Preventing back of knee pain

While not all causes of back of knee pain are totally preventable, there are some steps you can take to reduce your risk:

Proper exercise techniques

• Warm up before exercise and cool down afterwards
• Gradually increase the intensity and duration of your workouts
• Learn to use proper form in your activities, especially those involving running or jumping
• Include exercises that strengthen the muscles supporting your knees

Maintaining a healthy weight

Being overweight puts your knees under more pressure, which in the long run can lead to back of knee pain. To prevent these knee problems, aim to maintain a healthy weight by keeping a balanced diet and engaging in regular exercise.

Proper footwear

Wear shoes that fit comfortably, are the right size, and offer adequate support. If you’re a runner, for instance, it’s recommended you replace your shoes as the cushioning wears away. For certain activities or if you have specific foot issues, you might benefit from custom orthotics.

Living with back of knee pain

If you're living with chronic back of knee pain, there are ways to manage your symptoms and improve your quality of life:

Managing pain at home

• Use heat or cold therapy as recommended by your doctor
• Practice gentle stretching exercises
• Consider using a knee brace or support for activities that may cause your pain to flare up
• Try relaxation techniques to help manage pain and reduce stress

Exercises to strengthen the knee

On your doctor's approval, exercises that can help strengthen the muscles supporting your knee include:

• Straight leg raises
• Wall squats
• Hamstring curls
• Calf raises
• Always start slowly and make sure to stop if you experience pain.

Lifestyle adjustments

• Modify activities that exacerbate your pain
• Use assistive devices like a cane if recommended
• Consider low-impact exercises like swimming or cycling
• Ensure your work environment is ergonomically set up to reduce strain on your knees

Diagnosing back of knee pain

When to see a doctor

While some cases of back of knee pain may resolve with home care, it's important to know when to seek medical attention. Consider seeing a doctor if:

• Your pain is severe or persists for more than a few days
• You're unable to bear weight on the affected leg
• Your knee gives way or feels unstable
• You notice significant swelling or redness
• You develop a fever along with knee pain
• You have a history of blood clots or risk factors for DVT
• Remember, early diagnosis and treatment can often lead to better outcomes and prevent complications.

Get help with your back of knee pain at Circle Health Group

Back of knee pain can be a complex and challenging issue, and knowing what the causes, symptoms, and prevention methods are is the first step towards finding relief. Remember, everybody’s case is unique, and what works for one may not work for another.

Above all, don't ignore nagging or severe back of knee pain. The right diagnosis and treatment by a healthcare professional can avoid worsening of the condition and effective relief, helping you return to your normal activities.

Is it time to get help with your back of knee pain? Book an appointment online today with Circle Health Group or give us a call directly and we'll help you find the right specialist for you. Our experienced team of orthopaedic consultants and physiotherapists are here to provide expert care and guide you on your journey to recovery. Don't let knee pain hold you back – take the first step towards a pain-free life today.