“I’m Not Getting Any Younger”: Knees

Each edition of this series takes one complaint people put down to age, and asks the same questions every time: what goes wrong, what’s sold to you, what the trials show, what’s worth testing, and when not to wait. Everything is graded the same way, a supplement to the same standard as a drug or an operation. And there’s one standing section: what’s sold to you vs what works and can’t be sold.

The grades: Strong means large or repeated randomised trials agree. Moderate or Mixed means trials help but are smaller, less certain or disagree. Observational or Mechanistic means measured in people as they live, or in the lab, not tested as a treatment. No benefit means it was tested properly and didn’t work. Guideline means what NICE recommends.

1. Is it just age?

Partly. Knee osteoarthritis is more common as we get older, and NICE uses “45 or over” as one of its diagnostic signs. But age is a real variable with a smaller share than people assume. The useful question is which part of your knee problem is age and which part is something you can change: strength, weight, how much you move, and how you load the joint.

Two things worth knowing before you accept “it’s your age”:

• What a scan shows and what you feel often don’t match. Across population studies, between 15% and 76% of people with knee pain had osteoarthritis on X-ray, and between 15% and 81% of people with osteoarthritis on X-ray had pain (Bedson 2008). In ordinary people aged 50 to 90, an MRI found meniscal tears in 19% of women in their fifties and 56% of men over 70, and 61% of those with tears had had no recent pain, aching or stiffness (Englund 2008). A finding on a scan doesn’t by itself explain your pain. (If you’ve been told a meniscus tear “can’t heal”, read They Told Him It Couldn’t Heal.)
• Muscle responds at any age. Ten frail nursing-home residents, average age 90, did eight weeks of heavy strength training. Their strength went up by an average of 174%, and walking speed by 48% (Fiatarone 1990). Tiny, uncontrolled A demonstration, not proof. Tissue tolerance and how fast you can progress do change with age. Whether muscle can still respond doesn’t.

And one on mindset, graded honestly: people aged 50 and over with more positive views of their own ageing lived 7.5 years longer over 23 years of follow-up, after adjusting for age, sex, income, loneliness and health (Levy 2002). Observational It can’t tell us whether the outlook caused the longer life or reflected something else. But “I can’t at my age” is worth questioning before you accept it.

2. What NICE actually recommends

The UK guideline for osteoarthritis (NICE NG226, 2022) is clear and, for many people, surprising:

• It’s diagnosed clinically, usually without a scan, if you’re 45 or over, have activity-related joint pain, and have no morning stiffness or stiffness lasting no more than 30 minutes. Imaging isn’t routinely needed unless something is unusual.
• The core treatments are therapeutic exercise and, if relevant, weight loss. NICE says to “offer therapeutic exercise tailored to their needs” to everyone with osteoarthritis.
• It warns you honestly: pain may increase when you start exercising, and long-term adherence is what brings the benefit.
• On weight: “any amount of weight loss is likely to be beneficial”, and losing 10% of body weight is likely to be better than 5%.
• First medicine for the knee: a topical anti-inflammatory gel (a topical NSAID).

3. What’s sold to you vs what works and can’t be sold

What’s sold: joint supplements, electrical muscle stimulators, braces and supports, injections, and keyhole surgery. Some of these are advertised heavily, sometimes by famous faces.

What works best: getting stronger, moving more, and carrying less weight. Nobody can patent a squat, so nobody advertises it.

That’s not a dig at everything in a bottle or a box. Below is how each one did in trials, graded the same way.

Things you do

The honest reading of the exercise evidence: it helps most people a moderate amount, it’s safe, and its benefits don’t stop at your knees (exercise also lowers blood pressure; see the heart markers post). But the 2024 Cochrane update is right that the average benefit is smaller than people expect. That’s a reason to do it properly and stick with it, not a reason to buy something instead.

Things that are sold

Fair to the devices: electrical stimulation can help someone who can’t yet contract their thigh muscle properly, for example after surgery, as part of supervised rehab. That’s not the same as a gadget doing your exercise for you.

Conventional treatments, same standard

Notice the pattern. Some of the most expensive conventional options failed their trials too. The standard I use doesn’t care whether something comes from a pharmacy, a clinic or a health-food shop.

Myth: “never let your knees go past your toes”

Plenty of people were taught this, and some are now afraid to squat at all. In a small lab study, seven trained men squatted with and without a barrier stopping their knees travelling forward. Blocking the knees cut the load at the knee a little, but the load at the hip went up roughly tenfold, with more forward lean of the trunk. The authors concluded that good loading “may require the knees to move slightly past the toes” (Fry 2003).

My view: the knee is often the victim, not the culprit

This is my strongest position on knees, and it comes from nearly forty years of watching people move rather than from a trial. I think of the knee as a slave joint. It sits between the ankle and the hip and does what they let it do. In running, jumping, changing direction, and even something as ordinary as a squat, the load is meant to be shared across all three joints bending together: ankle, knee and hip, what coaches call triple flexion. When one link can’t play its part, something else has to make up for it.

The most common missing link I see is the ankle. If it can’t bend forward enough, the knee and the hip take more than their share, and in fast or agility movements the knee takes the worst of it. The other is timing. Moving well is a coordinated skill, with a rhythm to it, and people lose that skill without noticing. When it goes, the joints stop sharing the load, and both how much you can carry and how well you move suffer.

I hear “it’s arthritis” a lot. Sometimes it is. Often, in my experience, it’s overuse, with or without faulty movement. And many times, when we correct the movement skill, people have less pain in the moment and less joint pain after exercise.

4. What’s worth testing

For knee osteoarthritis itself, I wouldn’t sell you a blood test. No blood test diagnoses it, and NICE says a scan usually isn’t needed either.

What is worth checking:

• With your GP: morning stiffness that lasts longer than 30 minutes, swelling in several joints, or a hot swollen joint. These point away from osteoarthritis and need medical tests.
• What you can measure yourself, or with me: how far your knee can travel forward over your toes with the heel down (ankle bend), thigh strength in each leg compared side to side, how long you can hold a single-leg position, how you get up from a chair without your hands, your weight over time. These change with training, and they’re what the exercise trials actually move.
• Your wider health, because the same habits drive both: HbA1c, blood pressure and weight. See the heart markers post.

5. When not to wait

From NHS guidance on knee pain (Midlands Partnership NHS Foundation Trust).

Go to A&E if:

• your knee or leg looks newly deformed or misshapen;
• your knee is locked and won’t move, or you can’t put any weight through your leg;
• you have severe knee pain with redness or heat around the knee and you feel unwell (this can be a joint infection);
• you’ve had a serious fall or injury, especially if you have osteoporosis.

See your GP if:

• you feel unwell, have a fever or unexplained weight loss;
• your knee locks or gives way when you put weight on it;
• the pain has suddenly got much worse despite self-help, or hasn’t improved after a couple of weeks.

Throbbing pain and swelling in one leg, usually in the calf or thigh, can be a blood clot (DVT). The NHS says to ask for an urgent GP appointment or get help from NHS 111, and to call 999 or go to A&E if you also feel short of breath or have chest pain.

6. Where to start

1. Get a diagnosis you trust. If it fits the NICE picture, you probably don’t need a scan.
2. Look above and below the knee. Check your ankles and hips, and how you squat, step and land, before blaming the knee itself.
3. Start strengthening and keep going. NICE warns pain may increase at first; that’s expected, not a sign to stop. Any type of exercise counts; consistency matters more than the programme.
4. If you’re carrying extra weight, any loss helps, and 10% helps more than 5%.
5. Before buying anything, check it against the tables above.
6. Don’t stop or start medicines without your GP or pharmacist.

I’m a personal trainer as well as a nutrition practitioner, so I have an interest in telling you exercise works. I also sell supplements. That’s why both are held to the same standard here, and why the evidence on exercise is reported as modest where it is.

Sources

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