Three things to stop doing with a sore knee.

A sore knee changes how you live before you've noticed it happening. You take the lift. You stop the class you liked. You start planning your day around what your knee will put up with.

Most of what people do next makes it worse. Not because they're careless — because the obvious things to do are the wrong ones. Here are the three I see most.

1. Stop resting it completely.

Rest feels like the sensible, careful choice. For a knee, it's usually the opposite.

The muscles around your knee — the front of your thigh, your calves, your hips — are what hold the joint steady and absorb the load when you walk, climb and stand up. When you stop using them, they weaken. A few weeks of "being careful" and the knee has less protection than when the soreness started. That's how a sore fortnight turns into a sore year.

Moving a sore knee within what it can comfortably do isn't reckless. It's what keeps the machinery working while things settle. Shorter walks rather than no walks. The shallow stairs rather than the lift, when it's tolerable. Gentle, regular, unremarkable movement.

Instead: keep moving in the range that feels manageable, a little and often, and let comfort — not fear — set the limit.

2. Stop pushing through sharp pain.

The other camp does the opposite: no pain, no gain, walk it off. That's not braver — it's just the other way of making it worse.

There's a difference worth learning. A mild ache that eases as you warm up, and settles within a day, is usually a knee being asked to work — that's often fine, and often useful. Sharp pain, pain that makes you limp or change how you move, swelling, or an ache still shouting the next morning — that's a knee telling you the dose was wrong. Not that movement is wrong. That this much, this fast was wrong.

Instead: use the next-day test. If the knee has settled by the following morning, yesterday's amount was fine. If it hasn't, do less next time — don't stop, shrink the dose.

3. Stop stretching as the only fix.

Stretches feel productive, they're what everyone recommends, and they're pleasant enough. But most sore knees aren't sore because something is tight. They're sore because something is weak — and a weak muscle can't be stretched strong.

If the sore knee struggles most going down stairs, standing up from low chairs, or on slopes, that points at muscles that can't yet control the load — most often the front of the thigh and the hips. Building that control back is slow, boring, and it works. Stretching alone is none of those things: quick, pleasant, and — on its own — mostly a way of feeling busy while nothing changes.

Instead: strength work, started at the level your knee can actually tolerate today, progressed gradually. That's most of what real knee rehabilitation is.