My knees started complaining about stairs right around the same time I stopped playing sports. Going down was worse than going up, and a flight of stairs in the morning sounded like someone cracking knuckles inside my leg. A physical therapist friend watched me walk one staircase and pointed out every mistake I was making.

Going down is harder on knees

Descending stairs puts several times your body weight through the kneecap, which is why going down hurts more than going up for most people. The fix starts with technique. Step down with your whole foot, not just the ball. Land softly and let your leg muscles control the descent instead of dropping your weight onto a straight leg.

Use the railing and lead with the strong leg

The railing exists for a reason. Hold it and let your arm share the load. If one knee is stronger, lead with that leg going up and lead with the weaker leg going down, so the strong leg controls the lowering. It feels odd at first but it takes real pressure off the sore knee. I do this automatically now on every staircase.

Strengthen the muscles that protect the knee

The best way to protect knees on stairs is to make the surrounding muscles stronger. Quads, hamstrings, and glutes all support the knee joint. Simple exercises at home: slow sit to stand from a chair, wall sits for thirty seconds, and step ups on the bottom stair holding the railing. You do not need a gym. A few minutes a few times a week makes stairs noticeably easier within a month.

Watch your shoes and your weight

Two silent knee killers: bad shoes and extra pounds. Thick, grippy soles reduce the impact of each step. Slippery socks on stairs are an accident and a knee injury waiting to happen. And every extra pound adds roughly four pounds of force across the knees with each step. Dropping even a little weight eases the load more than any exercise.

• Do not lock your knees at the top of the step. Keep a slight bend.
• Do not carry heavy loads one handed while on stairs. It twists your body.
• Do not rush. Fast stairs mean hard landings.
• If stairs hurt sharply or swell, see a doctor. Do not just push through it.

My stair pain did not vanish overnight, but it faded steadily over a few months of better technique and simple strength work. Your knees are telling you something, and most of the time the answer is better mechanics and stronger legs, not less movement.