If your knee hurts when bending, you’re not alone – many people experience knee pain when fully bent or feel soreness at the front of the knee. This blog explores the most common causes of pain when bending the knee fully, from traumatic injury to joint degeneration. You’ll learn how each condition typically presents, how it may affect daily movement, and which strategies can help ease discomfort.

More than a quarter of adults suffer from regular bouts of knee pain. It’s no surprise as our knees handle a tremendous amount of stress daily.^1-2 Scientists have found that for every pound of bodyweight, our knees are subjected to up to seven pounds of pressure when bent or weight-bearing.³

If you’re here, it is because you’ve noticed that your knee hurts when bending it, it is painful walking downstairs and feels uncomfortable while squatting. The fix for this really depends on the diagnosis. Below are some common causes of knee pain.

How Did You Hurt Your Knee?

Traumatic injuries are noticeable right away and worsen dramatically the next day as pain and inflammation set in. traumatic injuries typically occur playing sports, during slips, falls, and other work-related accidents. The trauma is caused by the injury exceeding the tolerance of knee structures leading to breaks, ruptures or tears.

Knee ligaments, bones, and menisci are the most commonly damaged structures in the knee joint. Injuries to bone and connective tissue result in long term pain and will impede normal knee function for some time after the initial injury. Less serious traumatic injuries may result in only painful, superficial contusions (bruises) which heal relatively quickly. If you believe you have incurred serious knee trauma you should visit a doctor as soon as possible. If bone or connective tissue within your joint is damaged a surgical assessment could be required.

A torn ligament in the knee, such as the lateral collateral ligament (pictured) can be behind a sudden onset of knee pain. 

Overuse injuries typically cause knee pain that comes and goes and varies in intensity. Sometimes our favorite activities subject our knees to stressful movement patterns repetitively. Think jumping, squatting, kneeling, running, lunging type movements. Moving in this way over and over again can irritate knee structures such as bursae, tendons, and articular cartilage.

IT Band Syndrome is a common overuse injury that occurs from excessive running. It occurs from irritation caused by the ilitibial (IT) band rubbing against the knee.

Degenerative Joint Disease (arthritis) is the number one cause of long term disability relating to knee pain. Pain often comes on slowly and over time those affected by arthritis will experience constant pain while performing weight-bearing activities.

Knee arthritis comes in a variety of forms, osteoarthritis being by far the most common. Osteoarthritis develops over a long period of time and your knee may not hurt during the early stages of the disease. Once your cartilage has worn away, bone on bone pressure develops within the joint. This causes pain as pressure is placed on the knee.

As the disease progresses, bone spurs begin to develop resulting in joint stiffness and mobility losses. Osteoarthritis is most common in people over 50 with those that are younger being much less likely to experience the disease. While age is a major influencer of arthritis progression it is only one of many predisposing risk factors to consider.

Where Does Your Knee Hurt?

Knee pain on the front of the joint could be patellar arthritis or patellar tendonitis. These conditions tend to hurt when bending the knee, kneeling and/or squatting. Typically the deeper the knee bend the worse it will hurt.

Pain on the lateral or outside of the knee is common in runners. Iliotibial band syndrome is one of the most common knee ailments affecting the lateral aspect of the knee.

The discomfort localized to the medial or inside of the knee could indicate tibiofemoral arthritis or meniscal irritation.  

Nagging pain or pressure that is localized to the back of the knee could be a sign that you’ve damaged your meniscus. It is also possible that you irritated the popliteal muscle and surrounding area.

My Knee Hurts When Bending: What to Do

1. Manage the Pain

Knee pain is usually the result of inflammation – a natural response from your immune system to damaged joint tissue. Pain and inflammation are completely normal and necessary for proper joint healing. Despite being “natural” joint inflammation can negatively influence your quality of life. Your knee may hurt so much that it makes day to day tasks difficult. In such cases, reducing inflammation with NSAIDs, the R.I.C.E. method and exercise are often used to manage pain in the short-term.

2. Get a Professional Knee Exam

Getting your knee assessed by a healthcare professional is crucial. This is even more important if you have suffered a traumatic knee injury. A definitive diagnosis will give you peace of mind and help expedite the healing process.

3. Try Different Treatments

If you are lucky, your knee pain may get better on its own with rest. However, more than likely you will need to engage in rehab exercises to overcome the injury. Physiotherapists specialize in providing specific exercises and treatment regimes that increase the strength, stability, and mobility of your joint.

Tip from our bracing specialists

Knee pain when fully bent is commonly linked to overuse or biomechanical issues in the joint. Reducing activities that involve deep flexion – like squatting or kneeling – can help manage discomfort, especially if the pain is localized at the front of the knee. Incorporating low-impact exercises and supportive gear, such as a Spring Loaded brace, may ease strain and reduce pain when bending the knee fully. People often find that bracing helps with bent knee pain at the front of the knee by offloading pressure and supporting proper alignment during movement.

Learn more or book a FREE consultation➡️

Additional Resources

• Complete Guide to Knee Pain
• Learn about Patellar Pain Syndrome
• Learn about Knee Osteoarthritis
• Knee Pain and Running

Frequently Asked Questions (FAQ)

1. What causes knee pain when fully bent?
Knee pain when fully bent can result from conditions like patellofemoral pain syndrome, meniscus tears, or arthritis. These issues can irritate structures inside the joint, leading to discomfort when the knee is deeply flexed.

2. Why is my knee sore when fully bent after exercise?
A knee that’s sore when fully bent after or during physical activity may be due to overuse, muscle imbalances, or inflammation in the joint. Activities involving repetitive bending, such as running or cycling, can strain the front of the knee.

3. Is knee pain when the knee is fully bent a sign of cartilage damage?
Knee pain when the knee is fully bent can indicate cartilage wear or damage, particularly under the kneecap. This is common in conditions like chondromalacia patella or osteoarthritis.

4. How can I reduce pain when bending my knee fully?
Pain when bending the knee fully can often be managed by modifying activities, improving joint alignment with a brace, and focusing on gentle strength and mobility exercises.

5. What could be causing bent knee pain at the front of the knee?
Pain at the front of the knee when bent is typically associated with patellofemoral joint issues or soft tissue irritation. This type of pain is common during squats, stairs, or prolonged sitting.