When your knee hurts as you bend and straighten it, this discomfort often signals an underlying issue within the knee joint. Understanding the reasons behind this pain can help you manage symptoms and seek care. The knee’s design, involving bones, cartilage, ligaments, and tendons, makes it susceptible to various conditions that cause pain during movement.
Common Reasons for Knee Pain
Patellofemoral pain syndrome, often called runner’s knee, is a common cause of pain around or behind the kneecap. This condition arises when repetitive activities, like running or jumping, cause irritation where the kneecap (patella) meets the thigh bone (femur) during bending and straightening motions. Misalignment or muscle imbalances in the thigh and hip can contribute to this friction.
Meniscus tears involve damage to the cartilage pads that cushion the knee joint between the shin and thigh bones. These tears can occur from twisting the knee and cause pain, swelling, and sometimes a catching or locking sensation when bending or straightening the leg. The pain is often sharp when the joint moves over the torn cartilage.
Osteoarthritis, a degenerative joint disease, involves the gradual breakdown of cartilage that covers the ends of bones. As this protective cartilage wears away, bones rub against each other, leading to pain, stiffness, and reduced flexibility when the knee is bent or straightened. The pain typically worsens with activity and improves with rest.
Tendonitis, an inflammation of tendons, can affect the patellar tendon (connecting the kneecap to the shinbone) or the quadriceps tendon (connecting the thigh muscles to the kneecap). Patellar tendonitis, sometimes called jumper’s knee, causes pain just below the kneecap during activities like jumping, running, or deep knee bending. Quadriceps tendonitis results in pain above the kneecap, aggravated by straightening the leg against resistance or ascending stairs.
Bursitis occurs when the fluid-filled sacs (bursae) that cushion the knee joint become inflamed. Several bursae surround the knee, and inflammation in one, such as the prepatellar bursa or pes anserine bursa, can cause localized pain and swelling. This pain intensifies when bending or straightening the knee due to pressure on the inflamed bursa.
Chondromalacia patella describes the softening and breakdown of the cartilage on the underside of the kneecap. This condition causes a dull, aching pain behind or around the kneecap, which worsens with activities that stress the patellofemoral joint, such as climbing stairs, kneeling, or prolonged sitting with bent knees. The rough cartilage can create a grinding sensation during movement.
First Steps and When to See a Doctor
When knee pain arises from bending and straightening, self-care measures can provide relief. The R.I.C.E. method is a recommended approach: Rest the knee, apply Ice packs regularly to reduce swelling, use Compression bandages to reduce fluid buildup, and Elevate the leg above heart level. Over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, can also help manage pain and inflammation.
Seek medical attention if the pain is severe or prevents you from bearing weight. Seek attention for a visible deformity or significant swelling that does not subside with R.I.C.E. If your knee locks, gives way, or makes popping noises accompanied by pain, it may indicate a more serious issue like a meniscus tear. Persistent pain that does not improve after self-care also warrants a visit to a healthcare provider.
Medical Evaluation and Treatment Options
A medical evaluation for knee pain begins with a discussion of your symptoms, including onset, aggravating/alleviating factors, and associated sensations like clicking or locking. The doctor will then perform a physical examination, assessing the knee’s range of motion, stability, and tenderness in specific areas. This examination helps identify sources of pain and guides further diagnostic steps.
Diagnostic imaging may be ordered to visualize internal knee structures. X-rays can reveal bone abnormalities, fractures, or signs of arthritis, while a magnetic resonance imaging (MRI) scan provides images of soft tissues like cartilage, ligaments, and tendons. These imaging results, combined with the physical exam, help confirm a diagnosis and inform treatment decisions.
Treatment approaches vary depending on the cause and severity of the knee pain. Physical therapy is often recommended to strengthen the muscles surrounding the knee, improve flexibility, and correct movement patterns. Medications, such as prescription-strength NSAIDs, may be prescribed to manage discomfort and inflammation. Injections, such as corticosteroids to reduce inflammation or hyaluronic acid to lubricate the joint, may provide temporary relief for certain conditions. Surgical interventions, like arthroscopy to repair tears or remove damaged tissue, or partial or total knee replacement in severe cases, are considered if conservative treatments are insufficient.
Long-Term Knee Health and Prevention
Maintaining strong muscles around the knee is an important step in preventing pain. Regularly performing exercises that strengthen the quadriceps (front of thigh), hamstrings (back of thigh), and glutes (buttocks) helps support the knee joint and distribute stress. Examples include leg presses, hamstring curls, and glute bridges.
Incorporating flexibility and stretching routines can also contribute to knee health. Stretching the quadriceps, hamstrings, and calf muscles can improve the knee’s range of motion and reduce tension that contributes to pain. Consistent stretching helps maintain muscle length and joint mobility.
Maintaining a healthy body weight reduces the load placed on the knees, which can alleviate and prevent pain, especially with conditions like osteoarthritis. Even modest weight loss can decrease stress on the knees and improve joint function. Choosing proper footwear that provides adequate support and cushioning also minimizes impact on the knees.
Modifying activities to avoid movements that aggravate your knee pain is an effective strategy. This might involve adjusting exercise routines or finding alternative low-impact activities like swimming or cycling. Always warm up before physical activity to prepare muscles and joints, and cool down afterward for recovery. Listening to your body and recognizing early signs of discomfort can help prevent minor issues from escalating.