Why Your Knee Hurts When Sitting: 5 Possible Reasons

At least one in four Americans experiences frequent knee pain. So you're upset—but perhaps not surprised—that it's happened to you. What does surprise you, though, is the seeming cause of your knee pain: sitting. You associate knee pain with activity. So, you wonder, "Why does my knee hurt when I get up from sitting?"

Several reasons could explain why your knee hurts when sitting. These include sitting too long or sitting in an awkward position. Poorly positioned furniture can also contribute. Finally, certain underlying conditions, like chondromalacia and arthritis, are associated with knee pain while sitting.

The Problem: Sitting for Too Long

Perhaps your job requires you to sit for long periods. If so, you might suffer from knee pain while seated on a daily basis. 

Or maybe your knee pain interferes with your enjoyment of otherwise fun activities. You can't savor a leisurely meal because your knees are aching. You keep putting off that trip because you can't bear the thought of sitting in a car or on a plane for hours. You don't even enjoy watching TV or movies anymore because you dread the pain.

If this sounds like you, you're not alone. And you may not even have something wrong with your knees. Instead, knee pain after sitting for long periods of time can be your body's natural response to an unnatural situation. 

Your body was designed for movement. It was not designed for a sedentary lifestyle. Researchers at Harvard Medical School have linked sitting for 6-8 hours a day to a host of negative health outcomes, including early death.

Knee pain is another less extreme but nevertheless problematic outcome of prolonged sitting. When you sit for extended periods, your muscles, ligaments, and tendons tighten. The result is pain. 

The Solution: Incorporate Movement

Fortunately, there are steps you can take to relieve the discomfort. And they don't involve quitting your job or putting enjoyable activities on hold. Rather, they begin with being aware of your activity level in various situations.

If you plan to be seated for long periods, get up and stretch periodically. The Harvard researchers suggest moving every 30-60 minutes. Doing so, even for short periods of time, can make a significant difference to your knees—and to your overall health.

So continue to work hard at your job. Maybe, though, you could take a walk to see a colleague instead of sending an email.

Enjoy that meal or movie, but stand and stretch once or twice even for just a few seconds.

Finally, plan that trip, but also plan rest stops or little side adventures along the way.

The Problem: Sitting in an Awkward Position

You don't have to sit for a long time to suffer from knee pain. The way you're sitting can also contribute. 

Perhaps you tend to sit with your legs crossed. Or maybe you enjoy curling up with your legs tucked beneath you.

Both of these positions are common. Initially, they can even feel comfortable. After even a short time, though, the pain sets in. This is because these positions put undue pressure on the kneecap.

The Solution: Sitting with Good Posture

If the cause of your pain is the way you're sitting, the solution is to change your position.

The best sitting position avoids crossed ankles and knees. Rather, proper posture while seated keeps both of your feet flat on the floor. If your feet don't reach the floor, adjust the chair, if possible. If not, use a footrest. Position your ankles just in front of your knees.

The seat of the chair should support most of your thighs. However, your knees should extend slightly so that there's a small gap between them and the front of the seat.

Your knees should also be parallel to or slightly lower than your hips. If you notice that your knees are too high or too low, again, adjust the chair, if possible. Alternatively, use a footrest to raise your knees or cushion beneath your glutes to lower them.

Once your lower body is positioned, check that your back is against the chair or use a cushion or backrest for support. Relax your shoulders and sit up straight. 

Finally, as before, remember to get up and move periodically if you'll be seated for a long time. Even the perfect posture is not healthy for extended periods.

The Problem: Non-Ergonomic Furniture

You may have noticed that the description of good posture above mentioned an adjustable chair, backrests, and footrests. These are features of ergonomic design. 

Ergonomic designs aim to make furniture and other aspects of the places people inhabit fit their bodies. In doing so, ergonomic designs reduce the stresses the body experiences, increase comfort, and promote overall health.

Unfortunately, some of the spaces people inhabit are still not designed with the body in mind. Partly, this is an issue of human diversity. Everyone's body is different. So a one-size-fits-all chair really doesn't fit all.

Partly, it's an issue of design flaws or poor consumer choices. Maybe you associate relaxation with sinking into a soft couch or chair. Unfortunately, that soft couch doesn't give your body the support it needs.

Finally, it's necessary to look at not just the furniture but the overall design of the space. This is especially important for spaces where you spend a great deal of time, like your car or office.

Sitting for long periods of time in an office chair that doesn't support your body can cause significant knee pain. In fact, it can cause significant pain in other parts of your body, like your back and neck, too.

The Solution: Choosing Ergonomic Furniture

Ergonomic furniture supports your body and enables you to maintain the proper seated posture described above. When shopping for furniture, keep the following guidelines in mind.

First, choose firmer, more supportive chairs when possible. Avoid furniture that allows your body to sink down into the cushions.

Also, look for an adjustable chair that you can position to fit your body. Many office chairs include a lever to adjust the height. This feature lets you raise or lower the seat so that, regardless of your stature, your knees are comfortably bent and your feet are flat on the floor. If an adjustable chair isn't an option, use a footrest.

Some chairs also include an adjustable back. Sometimes this involves a lever allowing you to tilt the back of the chair forward or backward. Other chairs include a manual or motorized pump that inflates or deflates the area that supports the lower back.

Look for these features and use them to ensure that your knees are resting at the proper angle and the back of your chair fully supports the length of your spine. Lacking these features, a backrest or pillow can support your lumbar region.

The Problem: Chondromalacia

Maybe you've taken stock of your habits, posture, and living spaces. You've made adjustments. Still, though, your knee hurts when sitting. If so, you may be suffering from an underlying condition, like chondromalacia.

Chondromalacia, or chondromalacia patellae, refers to the softening of the cartilage beneath the kneecap. As the cartilage breaks down, the knee and thigh bone rub together causing pain.

Chondromalacia Symptoms

Symptoms of chondromalacia include a dull ache in the knees. The discomfort is focused behind, below, and around the kneecap.

Patients also frequently experience a grinding sensation when they flex their knees. Common movements that cause this uncomfortable sensation include:

• Climbing or descending stairs
• Doing squats or knee bends
• Running downhill
• Standing up from a seated position

Chondromalacia Risks Factors and Causes

Chondromalacia is a common condition. A 2018 study found that almost 23% of Americans will experience chondromalacia. Among certain groups, this number is even higher.

The following factors increase a person's risk for developing chondromalacia:

• Excess body weight
• Excessive weakness or tightness in surrounding muscles
• Abnormal positioning of the kneecap  
• A history of injury to the kneecap
• Flat feet
• Certain activities like running, soccer, and bicycling
• Frequent exercise
• Age and gender: Adolescents and women are more likely to suffer from chondromalacia than other groups

Chondromalacia Diagnosis

If you're suffering from ongoing knee pain after sitting or any other activity, see a doctor. He or she can properly diagnose your condition and suggest treatment.

Your doctor will ask you to describe your symptoms and conduct a physical exam. Based on these findings, he or she may order more tests. These might include blood tests and X-rays to rule out other types of inflammation, including arthritis. If your doctor suspects chondromalacia, an MRI can confirm this diagnosis. In severe cases, arthroscopic surgery can provide a clear picture inside the knee.

The Solution: Chondromalacia Treatment

Most cases of chondromalacia can be treated conservatively. Your doctor will advise you to rest from your regular exercise routine. He or she may also suggest over-the-counter or prescription pain relievers. Icing your knee for 15-20 minutes three or four times a day can also help.

Your doctor will also suggest rehab exercises that you can do at home or under the guidance of a physical therapist. These exercises aim to strengthen the muscles around your kneecap.

Your doctor or therapist might also recommend supports, like taping or knee braces, to help the kneecap maintain proper alignment. Choosing supportive shoes or using shoe inserts can also help.

Finally, if you need to lose weight, your doctor can help you adjust your diet and activity. 

In some cases, symptoms don't respond to conservative measures. If self-care doesn't relieve your pain, your doctor can discuss other treatment options, including arthroscopic surgery.

The Problem: Osteoarthritis

Another underlying condition that causes knee pain while sitting is osteoarthritis. Osteoarthritis is a degenerative joint disease. This means that it involves the breakdown of the cartilage and underlying bone in the affected joints. In patients with osteoarthritis, in fact, the entire joint is affected, as connective tissues breakdown and the lining of the joint becomes inflamed.

The knees, hips, spine, and hands are the joints most frequently afflicted by osteoarthritis.

Osteoarthritis Symptoms

Symptoms of osteoarthritis usually develop gradually and tend to worsen over time. These symptoms include:

• Pain during or after activities
• Stiffness, especially upon waking or after periods of inactivity
• Tenderness to the touch
• Limited range of motion
• Grating, popping, or cracking sounds or sensations
• Swelling, warmth, redness, and other signs of inflammation

Osteoarthritis Risk Factors and Causes

Osteoarthritis is the most common type of arthritis, affecting 32.5 million Americans. Certain groups face a greater risk of developing osteoarthritis. These include:

• People who are overweight or obese
• Women
• African Americans
• Older individuals
• Those with a history of knee injuries or overuse
• People with a family history of osteoarthritis
• People with bone deformities or misalignments
• Diabetics

Osteoarthritis Diagnosis

Your doctor will use a description of your symptoms and a physical exam to evaluate your condition. If he or she suspects arthritis, blood work and X-rays can confirm the diagnosis. In some cases, your doctor may request an MRI or refer you to a rheumatologist for additional testing and treatment.

The Solution: Osteoarthritis Treatment

Osteoarthritis is a progressive disease. That means that it tends to get worse over time, and the damage is irreversible. Still, treatment options are very effective at managing symptoms and slowing the disease's progression.

Conservative measures include increasing your physical activity level safely under your doctor or physical therapist's care. A carefully designed physical therapy program can strengthen the muscles that support your knee joints. 

Increasing your activity level can also help you lose weight. For overweight or obese individuals, doing so can take some pressure off of the knees.

To support your increased activity level, your doctor or therapist might also recommend supportive devices, like crutches or canes.

Finally, conservative measures also include over-the-counter or prescription pain relievers. Cortisone injections can also provide longer-term pain relief. Of course, oral medications and injections involve risks. So you should discuss these risks with your doctor before choosing a particular method of treatment.

Many patients suffering from arthritis find some relief from conservative measures. Over time, though, the condition of the joint continues to deteriorate. If and when your arthritis significantly hinders your lifestyle, your doctor can discuss surgical treatment options. These include realigning and replacing damaged joints.

Don't Let Sitting Leave You Weak in the Knees: Causes and Solutions if Your Knee Hurts When Sitting

Knee pain when sitting has many causes, including prolonged sitting, improper posture, and poorly designed furniture. However, conditions, like chondromalacia and osteoarthritis, may also be to blame.

Regardless of the cause, you can take steps to relieve your pain. PowerRebound is here to support you as you do. Explore our full range of knee supports. 

Also remember that knee health is a component of your overall health. Healthy knees rely on healthy ankles and a healthy back—and vice versa. Check out the rest of our blogs for more advice on keeping all of your joints healthy and active.