The back outer corner of my knee hurts when I run downhill. What is it?

Why downhill is the trigger

The popliteus is a small muscle at the back of the knee whose tendon wraps around the outer side of the joint to attach to the thigh bone. It helps unlock the knee as it starts to bend, and it works hard when running or walking downhill, as it helps stop the thigh bone sliding forward on the shin.

A sudden increase in downhill or downstairs running, or running on a sloping road or beach, can overload the tendon faster than it adapts.

Typical signs

• Ache or sharp pain at the back outer corner of the knee
• Worse running downhill, going down stairs or walking down ramps
• Often comes on after a set distance, then settles with rest
• Tenderness just in front of the outer hamstring tendon with the leg crossed
• Usually no major swelling or locking

What you can do now

Cut back on downhill running and steep descents for a few weeks; flat routes, treadmills and cycling are usually tolerated. On cambered roads or the beach, alternate direction. Ice after runs can settle a flare.

Gentle strengthening for the hamstrings, calf and hips is a sensible start. If pain is sharp or getting worse despite these changes, stop running until it has been assessed.

When to be seen in Doha

Book an assessment if the pain lasts more than two or three weeks, follows a twisting injury, or comes with swelling, locking or a feeling of instability. These can point to a lateral meniscus tear or a posterolateral corner ligament injury instead.

At Aman Hospital, Dr. Gelber examines the knee carefully, including the ligaments, and arranges an MRI when needed.