Knee osteoarthritis affects approximately 5.4 million people in the UK, and much of the traditional "rest and wait" advice is outdated.

My name is Paul Carson. I am an MSc Physiotherapist registered with the HCPC (PH127231) and a member of the Chartered Society of Physiotherapy. I specialise in chronic MSK pain for adults over 65 through Fizzi Rehab.

In my online clinic, I often see patients who believe their knees are "bone on bone," yet clinical evidence shows that even with structural changes, you can achieve significant pain reduction through progressive loading (strength training).

Knee OA is a condition where the joint's natural repair process is overwhelmed by mechanical stress, leading to pain and stiffness. The most effective treatments are personalised exercise therapy, education, and weight management.

Research shows that 70% of patients see functional improvement within 12 weeks of starting a structured loading program (Čeh, T., et al. 2026).

This guide covers:

The Breakdown-Repair Imbalance · Red Flags · The Fizzi Sweet Spot Protocol.

OA is NOT ‘wear and tear’. We have substantial evidence that shows that it is a ‘disease’.

A disease is when an organ doesn’t behave as it should; in this case, it's our knee joint.

Normally, our joints, muscles and ligaments go through a continual process of breakdown, repair and improvement as we move, exercise and strengthen. 

This is ‘normal’, but OA changes this by increasing the breakdown but reducing the repair and improvement.

This can result in pain, stiffness and reduced joint space.

Your body can still repair and improve, but it's a bit messy. Almost a hasty response to the increased breakdown - we see irrational repair in the form of osteophytes, little chunks of bone that can be seen on X-ray. 

In fact, education is core to any effective osteoarthritis treatment plan! Exercise, drugs or surgery are less effective on their own.

Luckily, you are here, so you will always get the most up-to-date information.

If you experience any of these, contact your GP or call NHS 111 immediately.

The most important thing to understand about treating knee OA is this: the joint does not need to be protected from movement. It needs to be loaded intelligently. The Fizzi Sweet Spot Method uses two simple scales — the Pain Scale (target: 1–4/10 during exercise) and the Rate of Perceived Exertion (RPE, target: 7–9/10) — to find the exact training zone where your body builds new, resilient tissue without triggering a flare-up. Too little effort and you stay weak. Too much and you spike your pain. The Sweet Spot is the middle ground where real recovery happens.

Strengthening the muscles surrounding the knee — primarily the quadriceps, glutes, and hamstrings — is the single most evidence-backed intervention for knee OA. Here is the mechanism: when these muscles are strong, they absorb the compressive forces that would otherwise pass directly through the damaged joint surface. Think of them as shock absorbers. When they are weak, every step you take transfers that force straight into the cartilage.

A landmark systematic review by Bricca et al. (2019) analysed 21 randomised controlled trials and found that exercise therapy significantly reduced pain and improved physical function in knee OA, with no evidence of accelerating structural joint damage — even in patients with moderate-to-severe radiographic changes. In plain English: loading the joint does not wear it out faster. It makes it more resilient.

A second key study by Uthman et al. (2013), a Cochrane-level network meta-analysis of over 9,000 patients, found that strengthening exercise alone produced clinically meaningful improvements in pain and function — and that combining strengthening with aerobic exercise produced the best outcomes of all.

The Osteoarthritis Research Society International (OARSI) Joint Effort Initiative (2023) identified three core pillars of OA management that every treatment plan must include, regardless of severity: exercise, patient education, and weight management. These are not optional extras — they are the foundation that makes everything else work.

Exercise we have covered above. Education is equally important: understanding that OA is a disease of the breakdown-repair balance — not simple wear and tear — removes the fear of movement that keeps so many patients sedentary. Fear-avoidance (avoiding activity because you believe it will cause damage) is one of the strongest predictors of long-term disability in OA. The evidence is clear: movement is medicine.

For weight management, NICE guidelines (NG226, 2022) recommend that for every kilogram of body weight lost, the compressive load through the knee joint during walking reduces by approximately four kilograms. Even a modest reduction of 5–10% body weight produces clinically meaningful reductions in knee pain. At Fizzi, we integrate all three pillars into a remote-first plan — meaning you can address all three without leaving home.

Diet is not a replacement for exercise in OA management, but it is a meaningful adjunct. Chronic low-grade inflammation drives the breakdown side of the OA equation, and certain dietary patterns have been shown to modulate this process.

A systematic review by Veronese et al. (2022) found that adherence to a Mediterranean-style diet — high in oily fish, olive oil, vegetables, legumes, and whole grains — was associated with significantly lower pain scores and better physical function in OA patients. The proposed mechanism is a reduction in systemic pro-inflammatory cytokines (particularly IL-6 and TNF-alpha) that contribute to cartilage degradation.

The practical application is simple: you do not need a restrictive diet. Focus on increasing oily fish (salmon, mackerel, sardines) to 2–3 portions per week, replacing refined carbohydrates with whole grains, and adding a daily serving of leafy green vegetables. These changes are achievable, sustainable, and supported by the evidence.

Use this plan as your starting point. Every session follows the same two rules: keep your pain at or below 4/10 during exercise, and aim for an effort level of RPE 7–9 (meaning you could do 1–2 more reps if you had to, but it would be very hard). If pain spikes above 4/10, reduce the range of motion or switch to an isometric hold. If pain has not returned to your baseline level within 24 hours, reduce the load in the next session.

Q1 — Is knee osteoarthritis permanent?

A: While the structural changes shown on an X-ray are permanent, your pain levels are not. Most patients can achieve significant relief by improving the strength and shock-absorption of the muscles surrounding the joint.

Q2 — Can I exercise if my knee hurts?

A: Yes. We use the Sweet Spot Method: as long as your pain stays below a 4/10 and settles within 24 hours, the exercise is safe and beneficial for the joint.

Q3 — Do I need an X-ray or an MRI?

A: Usually, no. NICE guidelines (2022) state that OA can be diagnosed clinically in anyone over 45 with typical symptoms. Scans often show "age-related changes" that don't actually correlate with how much pain a person feels.

Q4 — What exercises are best for knee osteoarthritis?

A: The best exercises for knee OA are those that strengthen the quadriceps and glutes without loading the joint beyond a 4/10 pain threshold. Start with isometric exercises — isometric quad holds and wall sits — which build strength with zero joint movement. Progress to terminal knee extensions, step-ups, and split squats as pain allows. Aim for RPE 7–9 and 25 total reps per muscle group per session, 2–3 times per week (Bricca et al., 2019).

Q5 — Will knee OA get worse if I exercise?

A: No. This is the most common fear — and the most damaging myth — in OA management. A systematic review by Bricca et al. (2019) found no evidence that exercise accelerates structural joint damage, even in patients with moderate-to-severe radiographic OA. In fact, the opposite is true: inactivity leads to muscle atrophy, increased joint load, and faster functional decline. The key is staying within the Sweet Spot — RPE 7–9, pain ≤ 4/10 — so you load the joint without overloading it.

Q6 — How is Fizzi Rehab different from standard NHS physiotherapy?

A: Standard NHS physiotherapy for OA typically involves a limited number of in-person sessions with a generic exercise sheet. Fizzi Rehab delivers remote, one-to-one clinical assessment via HD video, a personalised Sweet Spot protocol specific to your pain levels and fitness, and ongoing support to hit your weekly goals. All sessions are delivered by Paul Carson (MSc, HCPC PH127231) — not a rotating team. You can book a 60-minute Clinical Pain Assessment at fizzirehab.com.

Written by Paul Carson, MSc Physiotherapist | HCPC: PH127231 | CSP Member Paul is the founder of Fizzi Rehab, specialising in MSK rehab for adults over 65. He developed the Fizzi Sweet Spot Method to bridge the gap between clinical safety and athletic ageing. Verify Paul's registration at hcpc-uk.org