Runner’s knee refers to pain around the kneecap and in the front of the knee joint. It is a common issue for runners and athletes who participate in large amounts of running and jumping.
Runner’s knee, also known as patellofemoral syndrome, often affects athletes and people who participate in high impact activities such as running, basketball, and soccer.
However, anyone can develop runner’s knee. It is one of the most common causes of anterior, or front, knee pain in adolescents and adults under 60 — about 3–6% of people in the United States have the condition.
The primary feature of runner’s knee is pain in or around the front of the knee that worsens when flexed or during weight-bearing activities. The pain may increase after long periods of sitting with the knees bent, such as when driving a car or sitting at a desk.
Read more to learn about runner’s knee, its causes, symptoms, and treatment options.
The knee is a complex joint, and knee pain and other issues are relatively common. Runner’s knee pain occurs when the patella — kneecap — does not slide smoothly over the femur, or thighbone.
The kneecap is a small bone that sits in front of the knee joint. It connects the quadriceps muscles — the large muscles in the front of the thigh — to the shinbone.
If the quadriceps muscles are too weak or too tight, they can cause the kneecap to track improperly. This can lead to friction and irritation of the cartilage under the kneecap, causing pain and inflammation in the knee joint.
Some cases of runner’s knee involve a condition called chondromalacia patella. This causes the articular cartilage under the kneecap to soften and break down.
The articular cartilage has no nerves, so it cannot directly cause pain. However, it can lead to inflammation of the connective tissue and pain in the bone.
Dull, aching pain around or behind the kneecap is the hallmark symptom of runner’s knee. The pain usually worsens after exercise and eases with rest, and it may be present in one or both knees.
Other symptoms include:
- pain during activities that repeatedly bend the knee, such as using stairs, running, or jumping
- pain in the front of the knee after sitting for long periods with the knees bent
- popping or crackling sounds in the knee
However, it is important to note that cracking sounds in the knee joint are not always a sign of an issue. These sounds are known as crepitus — if they are not accompanied by pain and do not cause any mobility issues, they are likely harmless.
Treatment for runner’s knee aims to reduce pain, improve patellar tracking, and return the person to their previous activity level.
The first line of treatment usually involves activity modification, nonsteroidal anti-inflammatory drugs (NSAIDs), and other conservative measures such as ice and rest.
Doctors commonly recommend using the RICE method:
- Rest: For several days, avoid activities that increase pain.
- Ice: Apply wrapped cold packs for 20 minutes several times per day.
- Compression: Lightly wrap the knee in an elastic bandage with a gap over the kneecap. Ensure the bandage fits snugly and does not cause pain or cut off circulation.
- Elevation: Elevate the knee higher than the heart whenever possible. A person can try lying down and propping their knee up on pillows.
After the acute phase, a person enters the recovery phase, which aims to correct the underlying issues of runner’s knee.
Combining knee and hip exercises to increase strength, mobility, and leg function is the most effective method. Other alternative treatments may offer relief. However, there is little research and evidence that they are effective, so most doctors and physical therapists do not recommend them.
- knee braces
- manipulation therapy
- electrophysical therapies such as ultrasound or TENS
Doctors do not generally recommend referral to an orthopedic surgeon. They consider this a last resort after trying more conservative therapies.
The recovery time for runner’s knee varies depending on the individual, the severity of the injury, and how they follow their treatment plan. In most cases, people recover within 8 weeks.
After this time, if the pain has not improved, a doctor may order imaging tests to rule out osteoarthritis, patellar fractures, or other conditions.
Runner’s knee occurs when the back of the kneecap contacts the thigh bone. Experts
- Overuse: Repeated stress on the knee, such as activities including running, football, and basketball, can cause injury.
- Muscle imbalance: When the muscles around the knee are not aligned, it can place extra stress on the kneecap, leading to injury.
- Trauma: A direct injury to the kneecap can contribute to the development of runner’s knee.
Prevention is not always possible, but some measures may reduce the risk of runner’s knee, including:
- strengthening the leg muscles with exercises
- wearing appropriate shoes for the activity
- warming up properly before exercise
- increasing training gradually instead of suddenly
- reducing activities that have previously hurt the knees
- maintaining a moderate body weight
People should consult a doctor if knee pain does not improve with rest and home remedies.
If the knee is swollen, discolored, or hot to the touch, these may be signs of infection or inflammation that warrant medical attention.
Runner’s knee is a common injury that can cause pain around the kneecap. Causes include overuse, muscle imbalance, and trauma.
Treatment involves activity modification, NSAIDs, and other conservative measures such as rest, ice, compression, and elevation. In most cases, people recover within 8 weeks.
People can reduce the risk of runner’s knee by strengthening the leg muscles, wearing appropriate shoes, and gradually increasing training.