You may not be familiar with bursae, but they may very well be your knees' best friends. These fluid-filled sacs in your knee joint act like tiny pillows to reduce friction and cushion bones, tendons, and muscles, which helps you bend and straighten your knees. When a knee bursa becomes inflamed, it’s called knee bursitis. The condition may cause pain that can limit your mobility. 

Bursitis in the knee is pretty common, and it’s also very treatable. There are many at-home treatments you can try to feel better if you’re having a pain flare due to knee bursitis. Hinge Health physical therapists say that doing regular exercises to stretch and strengthen your knee joint can also help prevent bursitis from happening again. In fact, one Hinge Health member recently told us that doing exercise therapy is helping them navigate knee pain related to bursitis. “Although I still have pain flares in my left knee, it is manageable,” they shared. “Now I can climb stairs, get off the floor, bend, and do other types of exercises — like Zumba — without much effort or pain.”

Here, learn more about knee bursitis — what causes it, how it’s treated, and the best knee exercises to help. 

What Is Knee Bursitis?

Knee bursitis occurs when a bursa in your knee becomes irritated or inflamed. These small, fluid-filled sacs cushion an area to prevent your bone from rubbing on your muscle, tendon, or skin — thereby preventing friction and inflammation. 

You have more than 150 bursae in your body, including four main bursae in each knee. Knee bursitis most commonly occurs over the kneecap (aka the patella). Prepatellar bursitis, as it’s called, is the second most common type of bursitis in the entire body. 

“Prepatellar bursitis is most common with prolonged kneeling. We often see it in people who have jobs or hobbies like construction or gardening,” says Lori Walter, PT, DPT, a physical therapist at Hinge Health. 

Another common type of knee bursitis, pes anserine bursitis, is more common in athletes. “The pes anserine bursa sits on the inside of the knee below the joint. It can be affected by hamstring tightness and tightness on the inside of the thigh, which can be common among athletes,” says Dr. Walter. 

Symptoms of Knee Bursitis

If a bursa becomes inflamed, more fluid collects inside it than usual, which causes it to swell. This excess fluid can cause pain, discomfort, and sensitivity to pressure. Depending on the severity, it may not hurt when you’re resting, but you may not be able to bend or move your knee like you usually do. 

The affected portion of your knee might also be warm, tender, and swollen. With prepatellar bursitis, the knee can look bigger than usual and seem “squishy” (like a water balloon when you press on it).

Several things can cause symptoms of bursitis to appear rapidly, like direct trauma or infection. But most cases of knee bursitis occur due to repetitive stress from irritation of a bursa, so symptoms usually begin gradually and worsen over time.

Causes of Knee Bursitis

Here are some of the most common reasons you may experience knee bursitis.

• Frequent, sustained external pressure. Typically, this results from prolonged kneeling, which likely affects people who work on their knees for long periods, such as construction workers, plumbers, and gardeners. (Fun fact: Prepatellar bursitis used to be called housemaid’s knee, carpet layer’s knee, and carpenter’s knee, because people in those jobs tended to kneel a lot and were more prone to knee bursitis.)

• Doing more activity than your knee is ready for. Pes anserine bursitis can occur due to repetitive knee movements from playing sports like soccer or tennis. Muscle weakness and tightness, for instance in the hamstring (back of the thigh) muscles, can also increase pressure on the bursae. However, the message here is not to avoid doing activities like this. Rather, it’s to continue being active while adding knee stretches and strengthening moves to your routine. This trains your knees and pain system to adapt and handle these activities with less pain.

• Trauma. An injury — such as tripping and landing on your knee — can damage the bursae and cause sudden swelling.

• Infection. Bursitis is usually not infectious, but the prepatellar bursa can become infected — for instance, if a scratch, insect bite, or cut on your knee becomes infected and spreads to your bursa sac. Symptoms include red, hot, painful, and swollen skin. The condition is serious and requires immediate medical treatment.

• Complications from arthritis or gout in the knee. Sometimes inflammatory diseases such as rheumatoid arthritis and gout can affect the bursae in the knee, causing bursitis.

How Is Knee Bursitis Diagnosed?

Knee bursitis can usually be diagnosed pretty easily from a medical history and physical exam since the swelling can often be felt and seen from the outside. But knee bursitis, along with other knee diagnoses, is often characterized as an episode of non-specific knee pain. This means more serious knee conditions are quite rare, and unless your doctor suspects something more serious, imaging and other tests are sometimes not necessary. 

So as long as you don’t have signs of an infection, you don’t need to be diagnosed with bursitis in order to start treating your symptoms and begin healing. Even if you don’t have a specific diagnosis, you should feel safe to move when you experience symptoms consistent with knee bursitis.

Treatment Options for Knee Bursitis

Treatment for knee bursitis focuses on relieving pain and inflammation to improve knee mobility. It includes:

• Adjusting your usual activities. It’s helpful to give your knee a break from any aggravating activities, like repetitive kneeling or bending, but you don’t want to rest it completely. Tissue around the knee can become stiff and weak with too much inactivity, so Dr. Walter recommends “relative rest.” This might mean walking or biking instead of running and jumping, or just scaling back on the intensity or duration of certain activities. If walking is a challenge, consider using a cane or a crutch to give yourself some support until you start to see some improvement. “Relative rest could also mean gentle, non-weight-bearing exercises, like bending and straightening your knee without putting pressure on it,” she says. 

• Applying compression. Compression in the form of an elastic bandage or a knee sleeve can keep the knee from becoming more swollen and help reduce discomfort.

• Elevation. You can elevate your knee a few times a day for 15 or more minutes after you’ve been on it for an extended period to help reduce inflammation.  

• Applying ice. Ice your knee at regular intervals (you can ice while elevating your knee) to reduce swelling and pain. 

• Taking over-the-counter (OTC) medication. Pain relievers such as ibuprofen (Advil, Motrin), naproxen (Aleve), and acetaminophen (Tylenol) can be helpful for knee bursitis pain. It’s important to make sure that you are safely able to take these medications, based on your medical history.

Stretching and strengthening exercises are both helpful for managing knee bursitis. For instance, tight tendons and muscles can place extra stress on bursae and cause more friction when you move your knee, leading to inflammation, swelling, and pain. Restoring muscle strength is also important, says Dr. Walter. “Muscle weakness often leads to tightness when a muscle doesn’t have the control to contract and relax in a smooth way,” she explains. “Strong muscles provide support around the knee, decreasing inflammation from overuse.” These moves recommended by Hinge Health physical therapists will help to steadily improve flexibility, range of motion, and strength in your knees.

The information contained in these videos is intended to be used for educational purposes only and does not constitute medical advice or treatment for any specific condition. Hinge Health is not your healthcare provider and is not responsible for any injury sustained or exacerbated by your use of or participation in these exercises. Please consult with your healthcare provider with any questions you may have about your medical condition or treatment.

Knee Bursitis Prevention Tips

To avoid knee bursitis or prevent its recurrence, try to:

• Take breaks when you kneel or squat. To avoid irritating your bursae when you’re on your knees for long periods of time, take regular breaks to stretch your legs.

• Adjust how you squat temporarily. If you have to squat a lot as part of your job, try not to squat all the way down. Shortening the arc to just 45 degrees takes pressure off your knees. Note: This does not mean squatting is bad for your knees. In fact, squatting trains your knee joint to handle this movement and, over time, this can reduce your risk of bursitis. It’s just a matter of doing the activity in a gentle, modified way that gives your body time to adjust until it’s ready to handle deeper squats. 

• Keep moving. Movement and activity help to keep the structures in and around your knees strong and flexible, making them more resilient to pain flares and other issues such as bursitis. 

When to See a Doctor

Home treatments that include stretching and strengthening exercises often allow people to see improvement within a few weeks. Knee bursitis may, in some cases, indicate a more serious problem, such as a systemic infection. See a doctor if:

• Inflammation doesn’t improve with ice and gentle movement. 

• You have a fever. 

• Your pain is more generalized. “Bursitis is usually pretty localized, meaning you can put your finger where it hurts,” says Dr. Walter. “If your pain goes down your leg, it’s less likely to be bursitis.” 

PT Tip: Wear Knee Pads for Extra Cushioning

Although kneeling for prolonged periods can make a bursitis flare more likely, don’t feel like you have to give up activities that involve kneeling. When doing things like gardening, construction work, or playing certain sports, wearing knee pads or placing a pad under your knees helps disperse pressure evenly across your knees and minimizes the incidence of bursitis, says Dr. Walter. 

How Hinge Health Can Help You 

If you have joint or muscle pain that makes it hard to move, you can get the relief you’ve been looking for with Hinge Health’s online exercise therapy program. 

The best part: You don’t have to leave your home because our program is digital. That means you can easily get the care you need through our app, when and where it works for you.  

Through our program, you’ll have access to therapeutic exercises and stretches for your condition. Additionally, you’ll have a personal care team to guide, support, and tailor our program to you. 

See if you qualify for Hinge Health and confirm free coverage through your employer or benefit plan here.

This article and its contents are provided for educational and informational purposes only and do not constitute medical advice or professional services specific to you or your medical condition.

References 

1. Bursitis: Overview. (2018, July 26). National Institute of Health — Institute for Quality and Efficiency in Health Care (IQWiG). https://www.ncbi.nlm.nih.gov/books/NBK525773/

2. Prepatellar Bursitis. (2021, December 7). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/22189-prepatellar-bursitis

3. Sheth, N. P. & Foran, J. R. H. (2022, February). Prepatellar (Kneecap) Bursitis. American Academy of Orthopaedic Surgeons. https://orthoinfo.aaos.org/en/diseases--conditions/prepatellar-kneecap-bursitis/

4. Knee Bursitis. (2022, March 23). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/knee-bursitis/symptoms-causes/syc-20355501

5. Prepatellar bursitis. (n.d.). Retrieved from https://www.physio-pedia.com/Prepatellar_bursitis

6. Bursitis of the Knee. (n.d.). Beaumont. Retrieved from https://www.beaumont.org/conditions/bursitis-of-the-knee