Knee Pain

Knee pain splits usefully by age and pattern. In younger active people, patellofemoral pain (aching behind the kneecap, worse on stairs and after sitting) and patellar or quadriceps tendinopathy dominate, and both respond to graded loading rather than rest. In people over 45 with activity-related pain, morning stiffness under 30 minutes and no swelling, osteoarthritis is the working diagnosis and imaging adds little; X-ray findings correlate poorly with symptoms, and normal scans in painful knees are common. The most consistently effective intervention across the whole spectrum is quadriceps and hip abductor strengthening, which has effect sizes in osteoarthritis comparable to NSAIDs without the gastrointestinal and renal costs. Weight matters mechanically: each kilogram lost removes roughly four kilograms of load through the knee during walking, and 5-10% body weight reduction produces clinically meaningful symptom change. Two things to disregard. First, the idea that running destroys knees — cohort data show recreational runners have lower osteoarthritis rates than sedentary people. Second, the supplement mainstream: the NIH-funded GAIT trial found glucosamine and chondroitin no better than placebo overall. Curcumin has more consistent short-term data and collagen peptides show modest signals, but neither changes joint structure.

• •Aching pain with activity or stairs
• •Morning stiffness easing within 30 minutes
• •Grinding or crepitus
• •Swelling after use
• •Pain behind the kneecap after prolonged sitting
• •Giving way or instability

• •Knee osteoarthritis
• •Patellofemoral pain syndrome
• •Patellar or quadriceps tendinopathy
• •Meniscal tear or degeneration
• •Bursitis
• •Inflammatory or crystal arthritis

Cartilage loss and subchondral bone change in osteoarthritis, patellofemoral maladaptation with weak hip abductors, tendon overload from rapid training increases, meniscal degeneration, prior ligament injury, obesity increasing joint load, and inflammatory arthritis in a minority.