They say my knee cartilage is worn. Is it okay to walk?

Cartilage wears down, so why does every clinical guideline put exercise first?

Key points in 30 seconds

1. For knee osteoarthritis, the treatment that every major international guideline recommends first isn't injections or surgery, but exercise.
2. "Go easy on it" has a paradox built in. Cut back on activity, and your thigh muscles, the knee's shock absorbers, get weaker, so the joint actually takes more impact from the same step.
3. In an analysis pooling 44 clinical trials (3,537 people), exercise reduced pain by an average of 12 points out of 100, and the effect lasted more than 2–6 months after the program ended. Whether walking or strength training, there was no clear difference by type.
4. Acupuncture's effect was confirmed in data from about 17,000 people, but there is also a large trial that found no effect. We tell you both sides, and use it to help make a knee that can exercise.
5. If your knee is swollen and warm, hurts at night even at rest, suddenly locks, or started hurting after an injury, it may not be wear-and-tear arthritis, so we check that first.

What we often hear

• "They say my cartilage is worn. Is it okay to walk?"
• "I don't take stairs at all anymore, and I gave up hiking."
• "They say if you go easy on it, it'll last longer, so I move as little as possible."
• "It only feels better for a bit after an injection, then it hurts again."

Many people diagnosed with arthritis have already settled on an answer: go easy on it. The logic is that cartilage is a consumable, and using it wears it down.

That seems intuitive, but it's far from what clinical guidelines actually say. Major guidelines, including those of the American College of Rheumatology, the Osteoarthritis Research Society International and the UK's NICE, name exercise as the first step in managing knee arthritis. Let's look at the evidence for why a wearing joint needs exercise.

Arthritis isn't just a disease of the cartilage

If you see osteoarthritis only as "a disease where cartilage wears down," going easy on it looks like the answer. But it's a disease of the whole joint: the cartilage, the bone beneath it, the membrane around the joint, and even the muscles that protect the joint.

Here the muscles play a decisive role. Your thigh muscles are shock absorbers that share the impact landing on your knee with every step. If you cut back on activity to spare the knee, these absorbers weaken, and as they weaken, the joint takes more load from the same step.

Trying to spare the joint ends up pounding it more. The vicious cycle we saw in the spinal stenosis post, "you walk less because it hurts, and then you can't walk as far because you walked less," happens in exactly the same way in the knee.

Why alignment and weight can't be left out

The load on the inside of the knee is set by alignment multiplied by body weight.

In the bow legs post, we saw that legs bowing outward, or bow legs, are linked to arthritis developing and progressing on the inner side of the knee. Body weight is the value that multiplies that load. That's why managing arthritis means looking at alignment and weight together.

The evidence for exercise needs an honest look, down to its size

Exercise is the most thoroughly tested treatment for knee arthritis.

In a Cochrane review pooling 44 clinical trials and 3,537 people, land-based exercise such as walking or strength training reduced pain right after treatment by an average of 12 points on a 100-point scale. The evidence was rated high quality, and physical function and quality of life also improved. The effect continued for more than 2–6 months after the program ended. When the analysis was expanded to 139 trials in 2024, improvements in pain, function and quality of life were confirmed again.

Two points matter in practice.

First, there was no clear difference between types of exercise. Thigh strengthening, whole-leg strengthening, walking, and programs combining several exercises had similar effects. There's no reason to delay starting while searching for the perfect exercise. The good exercise is the one you can keep doing.

Second, the size of the effect should be read without exaggeration. The 2024 review compared the improvement with the smallest change patients feel as meaningful (12 points) and rated it small to moderate. Exercise isn't a cure-all. It's a foundation that builds steadily without increasing serious side effects.

Acupuncture's report card is mixed

The evidence for acupuncture in knee arthritis is more mixed than for any topic we've covered in this column series.

On one side is large pooled data. In an analysis combining individual patient data from 29 clinical trials that passed strict criteria, covering 17,922 patients, acupuncture reduced pain in chronic pain conditions, including arthritis, more than sham acupuncture and more than no treatment. In an update expanded to 39 trials, the effect lasted for a considerable time after treatment ended. A difference from sham acupuncture means the effect can't be explained by expectation alone.

On the other side is a large trial with the opposite result. In an Australian trial that divided patients aged 50 and over with chronic knee pain into acupuncture, laser acupuncture, sham laser acupuncture and no treatment, acupuncture did not improve pain or function more than sham treatment after 12 weeks (JAMA, 2014).

Put the two results side by side and you get this picture: the benefit of acupuncture compared with no treatment is seen fairly consistently, but the effect specific to acupuncture compared with sham acupuncture is small or, depending on the study, not confirmed.

So acupuncture's honest place is not "a treatment that fixes arthritis," but a role in lowering pain to make a knee that can exercise.

The limits of this evidence

Exercise trials can't be blinded. Patients can't help knowing they're exercising, so expectation effects mix into the results. The Cochrane review rated the evidence quality high even taking this into account, but part of the effect size may come from factors other than the exercise itself.

An average of 12 points is a group average. It mixes people who improve more with people who don't respond. You only know how one person responds by trying.

Acupuncture studies vary in their conditions. The type of stimulation, number of sessions and duration differ from study to study, so it hasn't been settled which conditions create the differences in results. Differences in design between the Australian trial (8–12 sessions over 12 weeks) and the trials in the pooled data also affect interpretation.

This isn't evidence that cartilage structure changes. For both exercise and acupuncture, the evidence is about symptoms and function, not about changing the course of the cartilage. Blurring this distinction becomes exaggeration.

So these are the standards we use

First, we sort out whether it really is wear-and-tear arthritis. If the knee is swollen and warm, hurts at night even at rest, suddenly locks or gives way, or started after an injury, other problems such as inflammatory arthritis or a meniscus tear need to be ruled out first. The most common trap is assuming it must be wear and tear because of your age, and moving on.

Second, we take "go easy on it" out of the prescription. Instead, we design the load. Activity within a range that doesn't greatly increase pain isn't something to cut back; it's treatment to protect. We rework activity into forms your knee can handle, such as walking in shorter bouts, flat ground first, and using support.

Third, we prescribe exercise as instructions, not prohibitions. People don't follow "don't do this" well. Rather than "be careful on stairs," "hold the railing and go down one step at a time, and walk on flat ground for 20 minutes a day" is what actually gets done. We tell you not what to avoid but what to do, down to the method and number of reps, and check at your follow-up visit.

Fourth, we address alignment and weight together. We check whether bow legs are also involved, and if weight plays a role, we add weight loss to the treatment goals.

Fifth, we tell you what to expect from acupuncture exactly as the report card says. Its role is to manage pain so you can exercise, and we also explain that there are conflicting study results.

How we work

We start by ruling things out. At the first visit, we check for swelling, warmth, night pain, locking and any past injury, and if needed, we look at the joint with X-ray and MRI in partnership with the radiology clinic on the 2nd floor of the same building. If an inflammatory condition is suspected, we refer you to the appropriate care first.

We measure the two variables of load. We use an X-body posture analysis to check leg alignment and bow legs, and an InBody test to check weight and muscle mass, to understand how load lands on this knee.

We make a knee that can exercise. We use acupuncture and pharmacopuncture (herbal acupuncture) to manage pain and swelling around the joint, and Chuna (Korean manual therapy) to work on the alignment and movement of the hips, knees and ankles.

We prescribe exercise as "do it like this." We set thigh and hip strengthening and walking to match your pain level, down to the method, reps and intensity, then check at your follow-up visit whether you're doing them and adjust. If weight plays a role, we set a weight loss goal together.

We review with pain and walking. We record your pain score, how long you can walk without resting, and how well you manage stairs, and compare them at set points. If things are heading the wrong way, we don't repeat the same treatment; we go back to ruling things out, and if your condition calls for a surgical assessment, we refer you there first.

How things progress differs from person to person depending on the state of the joint, alignment and weight, strength and your activity circumstances.

What changes

No longer looking for the elevator first when you face stairs. "Maybe I'll go for a walk today" no longer being a scary thought.

And seeing in numbers that the time you can walk without resting has grown since the day we first measured. That's what we're aiming for.

Sources used in this post

Source	What it studied	Result
Fransen et al., 2015	Cochrane review, 44 clinical trials, 3,537 people	Land-based exercise improved pain by 12 points out of 100 (high-quality evidence), improved function and quality of life, lasted 2–6 months after the program ended, similar effects across exercise types
Lawford et al., 2024	Cochrane review update, 139 clinical trials	Reconfirmed improvements in pain, function and quality of life. Effect size small to moderate relative to the minimal meaningful change
Vickers et al., 2018	Individual patient data meta-analysis, 39 clinical trials (first edition: 29 trials, 17,922 people)	In chronic pain including arthritis, acupuncture improved pain more than sham acupuncture and no treatment, with lasting effects
Hinman et al., 2014	Randomized clinical trial (JAMA), chronic knee pain in people aged 50+	At 12 weeks, neither acupuncture nor laser acupuncture gave pain or function benefits over sham treatment

References

1. Fransen M, McConnell S, Harmer AR, Van der Esch M, Simic M, Bennell KL. Exercise for osteoarthritis of the knee. Cochrane Database of Systematic Reviews. 2015;(1):CD004376. doi:10.1002/14651858.CD004376.pub3

2. Lawford BJ, Hall M, Hinman RS, et al. Exercise for osteoarthritis of the knee. Cochrane Database of Systematic Reviews. 2024;(12):CD004376. doi:10.1002/14651858.CD004376.pub4

3. Vickers AJ, Vertosick EA, Lewith G, et al.; Acupuncture Trialists' Collaboration. Acupuncture for chronic pain: update of an individual patient data meta-analysis. The Journal of Pain. 2018;19(5):455-474. doi:10.1016/j.jpain.2017.11.005

4. Hinman RS, McCrory P, Pirotta M, et al. Acupuncture for chronic knee pain: a randomized clinical trial. JAMA. 2014;312(13):1313-1322. doi:10.1001/jama.2014.12660. PMID: 25268438

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If you cut back on walking first after being told your cartilage is worn, please come see us once. We'll measure how much your knee can handle and decide with you what to start doing today. The order in which we examine the knee is laid out in our treatment guide.

For questions or appointments, message us in English through the messenger at the bottom right of the page, or call +82-53-716-1175.