Knee pain, particularly on the outer side when bending, is a common complaint that can disrupt daily activities. This discomfort, known as lateral knee pain, often develops gradually and can range from a dull ache to a sharp sensation. Understanding the structures involved and the potential reasons for this pain can provide clarity and guide appropriate steps toward relief.
Understanding Your Knee’s Lateral Side
The knee’s lateral, or outer, side relies on several structures for stability and smooth movement. The iliotibial (IT) band is a thick band of connective tissue running along the outside of the thigh from the hip to just below the knee, stabilizing both the hip and knee during activities like walking or running. The lateral collateral ligament (LCL) is a cord-like structure connecting the thigh bone (femur) to the smaller lower leg bone (fibula), providing stability against inward forces. The lateral meniscus, a C-shaped piece of cartilage, lies inside the knee joint between the femur and tibia, acting as a shock absorber and enhancing joint stability during bending.
Primary Causes of Lateral Knee Pain When Bending
Specific conditions affecting these structures frequently cause lateral knee pain when bending. Iliotibial Band (ITB) Syndrome is common, especially in athletes like runners and cyclists. This overuse injury occurs when the IT band repeatedly rubs over a bony prominence, causing irritation and inflammation. Pain is often sharp, aching, or burning, worsening with repetitive knee bending like running or climbing stairs.
A lateral meniscus injury is another source. Meniscus tears can result from twisting motions, direct trauma, or age-related wear. A tear can cause pain, tenderness on the outer knee, and sometimes clicking or locking, particularly with bending, squatting, or twisting. Swelling often develops within 24 to 48 hours following such an injury.
A lateral collateral ligament (LCL) sprain can also cause outer knee discomfort when bending. LCL sprains typically result from a blow to the inside of the knee, which stretches the ligament too far. Bending can irritate the injured ligament, leading to pain, tenderness along the outer joint line, and sometimes instability.
Lateral compartment osteoarthritis is another cause. This condition involves the wear and tear of cartilage on the outer side of the knee joint. As cartilage degenerates, bone may rub against bone, causing pain and stiffness aggravated by bending. Popliteus tendinopathy, an inflammation of the popliteus muscle tendon, can also contribute to lateral knee pain with bending motions.
Immediate Steps and When to Seek Medical Advice
Immediate steps can help manage lateral knee pain. Applying the R.I.C.E. method—Rest, Ice, Compression, and Elevation—is recommended. Resting the knee, applying ice packs (15-20 minutes several times daily), using a compression bandage, and elevating the leg can reduce pain and swelling. Over-the-counter pain relievers, such as ibuprofen or naproxen, can also alleviate pain and inflammation.
Seek professional medical attention for knee pain if:
- The pain is severe.
- You are unable to bear weight on the affected leg.
- There is significant swelling that appears suddenly or does not improve after a few days of self-care.
- There is a visible deformity of the knee.
- You heard a “popping” sound at the time of injury.
- The knee locks, buckles, or gives way.
A medical appointment is advisable if pain worsens, persists despite home remedies, or affects your sleep or daily activities.
Preventing Future Lateral Knee Pain
Proactive measures can help reduce the risk of developing future lateral knee pain. Incorporating a proper warm-up before physical activity and a cool-down afterward can prepare muscles and improve flexibility. Strengthening exercises targeting the glutes, hips, and core muscles can enhance overall stability and support for the knee joint. Maintaining flexibility in the IT band and hamstrings through regular stretching is also beneficial.
Choosing appropriate footwear that provides adequate support for your activities is important. Gradually increasing the intensity and duration of physical activity, rather than making sudden changes, helps prevent overuse injuries. Paying attention to proper form during exercises and sports can also minimize undue stress on the knee.