My inner knee aches after a long flight or sitting at my desk. Why?

Why sitting brings it on

With the knee bent for a long time, the kneecap presses into its groove and an irritated plica is held under tension against the thigh bone. When you finally stand up, the knee feels stiff and achy at the front, sometimes with a snap as it straightens. Doctors sometimes call this the moviegoer's sign.

It is common among expats on long-haul flights, people commuting long distances across Doha, students and office workers. It usually eases after a few minutes of walking.

Likely causes

• Plica syndrome: ache and sometimes snapping at the inner edge of the kneecap
• Patellofemoral pain: a more general ache around or behind the kneecap, also worse on stairs
• Chondromalacia patella: softened cartilage behind the kneecap with grinding
• Early arthritis: stiffness after sitting that eases with movement, usually from middle age

Practical steps for flights and desk days

• Choose an aisle seat on long flights so you can straighten the leg and walk every hour or so
• Straighten and bend the knee gently every 20 to 30 minutes while seated
• At work, set the chair so the knees are not sharply bent, and stand up regularly
• On long drives, stop for short walking breaks
• Do quadriceps exercises daily, such as straight leg raises and slow mini squats

On long flights, moving the legs and ankle pumps also lower the risk of blood clots, which is a separate but important reason to keep moving.

When to see a knee surgeon

Book an assessment if the ache has lasted more than a few weeks despite these changes, or comes with snapping, catching or swelling. After a flight, seek urgent care for a swollen, painful calf. At Aman Hospital in Doha, Dr. Gelber examines the plica, kneecap and meniscus, and explains which structure is likely responsible. Most patients improve with a focused physiotherapy programme.