Knee pain when running: check how your foot lands.

Running multiplies everything. Each landing carries more force than a step, and a run is thousands of landings in a row. A small habit that walking hides, a foot that turns out or an arch that drops, gets repeated under load until the knee notices.

That's why sprinters show the receipt. At speed there's nowhere to hide a leak. A runner's knee is the same idea at a slower pace.

Point forward, land under the hips rather than out in front, and push off through the big toe. With the feet straight and the arch working, each stride can spiral from the arch through the opposite glute to the opposite shoulder, and the knee stays a simple hinge in the middle.

With the feet turned out, the knee swings out, then caves over the arch as you land. If that sounds like you, start with the duck feet guide before you change anything else.

Maybe, but shoes rarely solve it alone. A worn-out shoe can be worth replacing. Heavily cushioned, narrow shoes can feel comfortable while letting the foot switch off. Wider, flatter shoes give the toes room to work, but switching quickly can overload calves and arches that aren't ready.

If you're thinking about minimalist running shoes, read barefoot shoes and foot strength first. The shoe is a tool. The foot still has to do the work.

Change one thing at a time, and change the body more than the stride:

• Cut the distance back if pain changes how you run. Limping miles teach new leaks.
• Add a few short form drills before runs: feet straight, quick light steps, push off the big toe.
• A slightly quicker step rate often keeps the landing under the hips.
• Twice a week, train single-leg strength: split squats, step-ups and calf raises with the big toe down.
• Build mileage slowly, by about a tenth a week at most.

If the knee hurts outside running too, read the main knee pain guide, and check your ankles with the ankle mobility exercises guide.