Why stairs are the first thing to go
Walking on flat ground asks your knee to carry roughly your body weight. Climbing stairs asks for three to four times that, and going down can ask for more still, because the muscles have to control your descent rather than simply push you up.
So stairs expose a problem long before flat walking does. People often tell us their knee is "basically fine" — and then mention they have been taking the lift for six months.
Up or down? The direction is a clue
- Worse going down is the more common pattern. Descending loads the kneecap and demands controlled, lengthening work from the thigh muscle. It often points towards the kneecap joint or a quadriceps that is not strong enough to control the load.
- Worse going up more often reflects difficulty generating force — weakness in the thigh or hip, or pain from the joint surfaces under compression.
- Both directions, with morning stiffness that eases after moving around is a pattern often seen with arthritic change in the joint.
- Giving way or locking on stairs is different again and should be assessed — it can point to a mechanical problem inside the joint.
The things that most often turn out to be involved
In younger and middle-aged people, pain around or under the kneecap is the most common finding. It is usually a load problem rather than damage: the knee is being asked to do more than the surrounding muscles can currently control.
From the forties onward, early arthritic change in the joint becomes more common. This matters less than people fear. "Wear and tear" on a scan does not decide how much pain you will have or how well you will move — strength and activity levels influence that far more.
In both groups the hip and the foot are often part of the story. A knee that rolls inward when you step down is frequently a hip-control problem showing up one joint lower.
What you can do now
- 1
Do not stop using stairs entirely
Avoiding them completely deconditions the exact muscles you need. Where it is painful, go slower, use the handrail, and lead with the stronger leg going up and the painful leg going down.
- 2
Build the thigh muscle
Quadriceps strength is the single most reliable thing that helps knee pain on stairs. Sit-to-stand from a chair, done properly and progressed gradually, is a good starting point for most people.
- 3
Do not ignore the hip
Side-lying leg raises and similar hip work reduce the inward collapse of the knee that makes stair descent painful.
- 4
Manage the load, not just the pain
A knee that hurts for hours after an activity was overloaded. Reduce the amount, keep the activity, and build back up.
Where physiotherapy fits
An assessment works out which of these is driving your pain — kneecap, joint surface, hip control, or a mix — and that determines the plan. The treatment itself is usually unglamorous: a specific, progressive strengthening programme, supported by hands-on work to settle pain and restore movement.
It takes weeks rather than days, but for most people it works, and it keeps working after the sessions end.
In short
- Stairs load the knee three to four times more than flat walking.
- Which direction hurts more is a useful diagnostic clue.
- Scan findings matter less than strength and activity levels.
- Quadriceps and hip strength are what reliably help.
See a doctor first if you have
- The knee locks, catches, or gives way without warning
- Marked swelling, especially if it came on rapidly
- The knee is hot, red, and painful — this needs same-day medical attention
- You cannot put weight on the leg after an injury
- Fever alongside a painful, swollen joint
This article is general information, not a diagnosis. If any of these apply to you, please get medical advice before starting exercise or physiotherapy.
