Knee pain experienced when the knee is fully bent can be a common and often disruptive issue, affecting daily activities ranging from simple movements like squatting to more complex physical tasks. This type of discomfort can signal a variety of underlying conditions within the knee joint, which is a complex structure involving bones, cartilage, ligaments, and tendons. Understanding the potential causes behind this specific pain can help in addressing the issue effectively.
Common Causes of Pain
Pain when fully bending the knee often stems from issues within the joint. A meniscus tear is a frequent culprit, involving the C-shaped cartilage cushioning the bones. Tears in this cartilage can cause pain, especially with deep knee bending or twisting motions, sometimes with clicking or locking.
Patellofemoral Pain Syndrome, commonly known as “runner’s knee,” causes discomfort around or behind the kneecap. This condition is aggravated by repetitive knee bending, such as squatting or kneeling. Osteoarthritis, a degenerative condition where protective cartilage wears down, is another common cause. This leads to stiffness and pain that intensifies with movement, including full knee flexion.
Bursitis, an inflammation of the small fluid-filled sacs (bursae) that cushion the knee, can cause pain during bending. Inflamed bursae can make deep knee flexion uncomfortable. Similarly, tendinitis, or tendon inflammation, can result in pain during bending movements, often due to overuse. Less common, certain ligament injuries, like a posterior cruciate ligament (PCL) tear, can contribute to deep knee flexion discomfort. These conditions can have overlapping symptoms, making self-diagnosis difficult.
Recognizing When to See a Doctor
While some knee pain resolves with self-care, certain symptoms warrant professional evaluation. Seek immediate medical attention for sudden, severe knee pain or inability to bear weight. Significant swelling, bruising, or obvious deformity also require prompt assessment.
A popping sound at injury, followed by pain and swelling, suggests a serious issue like a ligament or meniscus tear. If your knee locks, catches, or feels as though it is giving way, a doctor’s visit is warranted. Numbness or tingling below the knee, or pain persisting after a few days of rest and home care, signals a need for professional advice. Signs of infection, such as redness, warmth, or fever with knee pain, warrant immediate consultation.
Initial Steps for Relief
For immediate home management of knee pain, several steps provide relief. The RICE method (Rest, Ice, Compression, and Elevation) is a recommended first-aid approach. Resting the knee means avoiding aggravating activities.
Applying ice reduces swelling and pain by constricting blood vessels. Apply ice packs or cold compresses for 15-20 minutes every few hours, wrapped in a thin towel. Compression with an elastic bandage can help limit swelling; apply securely without restricting blood flow.
Elevating the leg above heart level reduces fluid accumulation. Over-the-counter pain relievers like NSAIDs can manage pain and inflammation. Acetaminophen is another pain relief option, though it does not reduce inflammation. Activity modification, avoiding painful movements, is important, alongside maintaining gentle range of motion.
Medical Evaluation and Diagnosis
When knee pain persists or worsens, a thorough evaluation pinpoints the underlying cause. Evaluation begins with a detailed medical history, covering pain onset, nature, prior injuries, and aggravating or alleviating factors.
A physical examination assesses swelling, tenderness, warmth, range of motion, and stability. Specific orthopedic tests may be performed to narrow diagnoses. Imaging tests (X-rays, MRI, ultrasound) visualize internal knee structures, identifying bone issues, soft tissue damage, or fluid collections. Accurate diagnosis is essential for an effective treatment plan.
Professional Treatment Options
Once diagnosed, professional treatment options address knee pain. Physical therapy is a cornerstone of treatment, strengthening surrounding muscles, improving flexibility, and correcting biomechanics to reduce joint stress. Therapists guide patients through targeted exercises and educate on proper movement.
Prescription medications, such as anti-inflammatory drugs or muscle relaxants, manage pain and inflammation. Knee joint injections offer localized relief. Corticosteroid injections reduce inflammation and pain. Hyaluronic acid injections lubricate and cushion osteoarthritic joints. Emerging options like Platelet-Rich Plasma (PRP) injections are explored.
Bracing or taping provides external knee support and stability, alleviating pain and protecting the joint. If conservative treatments are insufficient, surgical intervention may be considered. Procedures range from arthroscopy, a minimally invasive surgery for damaged cartilage or ligaments, to partial or total knee replacement for severe damage. Treatment choice is tailored to the specific diagnosis, condition severity, and patient needs.