Why does my knee hurt when I bend it?

Where it hurts when you bend

• At the front, around or behind the kneecap: the kneecap presses harder against the thigh bone as the knee bends, so patellofemoral pain and kneecap cartilage problems hurt on squats, stairs and kneeling
• Behind the knee at full bend: often the back part of the meniscus, a Baker's cyst, or swelling squeezed into the back of the joint
• On the inner or outer joint line when squatting or twisting: often a meniscus tear
• Just below the kneecap: the patellar tendon or the fat pad
• All round the knee, with stiffness: arthritis or general swelling

Why swelling makes bending painful

Even a small amount of extra fluid in the joint stretches its lining and makes the last part of bending tight and sore. If the knee looks puffy compared with the other side, or the dimples beside the kneecap have disappeared, swelling is likely part of the problem, and the cause of the swelling needs to be found.

Daily life in Qatar

Deep bending is part of everyday life here: sitting on the floor in the majlis, kneeling and sujood in prayer, and squatting. While the knee is sore, sitting on a cushion or a low stool, or praying on a chair, can reduce the strain. Patients who want to know the religious ruling on adapting prayer can discuss it with a scholar.

Keep the knee moving through the range that is comfortable, and strengthen the thigh muscles so they control the bend.

When to have it checked

Book an appointment if pain on bending follows a twist, if the knee catches or locks, if it is swollen, or if it has not improved after a few weeks. Seek urgent care if a swollen knee is also hot and red, or you have a fever.

At Aman Hospital in Doha, Dr. Gelber examines exactly where and at what angle the knee hurts, which often tells the kneecap, meniscus and joint lining apart.