Understanding Knee Osteoarthritis (OA)

Osteoarthritis (OA) is one of the most common joint disorders, especially in the knee. It’s a condition characterised by changes in the joint over time — involving wear and tear of cartilage, changes in bone, and fluctuating symptoms of pain and stiffness.

It tends to come in flares (bad periods) and remissions (better periods), rather than being consistently the same.

Although it can be distressing, it is non-inflammatory in the sense of classical inflammatory arthritis — it does not “spread” to other joints like rheumatoid arthritis typically does. OA is largely driven by mechanical, age-related and genetic factors rather than infection or systemic inflammation.

Although there is no complete cure, modern physiotherapy, exercise, and supportive treatments can dramatically improve symptoms, function, and long-term joint health.

How Does It Feel?

People with knee OA often describe a pattern of symptoms that reflect what’s happening inside the joint and around it.

Pain is usually worse with activity (especially loading the knee — for example, kneeling, getting up from a chair, or climbing stairs) and better at rest (though stiffness after rest or inactivity is common).

There may be difficulty with kneeling, rising from a seated position, or going up and down stairs, as these actions load the knee joint more heavily.

A sense of discomfort, aching or “grinding” in the knee is common, possibly with crepitus — a grinding or crackling sensation as the joint moves.

Because OA is a chronic condition, people often describe “good days” and “bad days” rather than a steadily worsening pain all the time.

On a “good day,” things may be manageable; during a flare, the knee can feel angry, swollen, or stiff. Although swelling in OA is usually mild compared to inflammatory arthritis, there can be changes in joint fluid or synovial irritation.

Diagnosis

Diagnosis is primarily clinical, with imaging used as needed.

Typical features include:

• Pain with joint use, minimal pain at rest

• Morning stiffness lasting less than 30 minutes

• Reduced movement or function

• Crepitus (grinding noise)

• Possible swelling without warmth or redness
  

Investigations:

• X-ray may show joint space narrowing and bony changes (osteophytes).

• MRI is rarely needed unless another injury is suspected.

Recent guidelines (EULAR 2023, NICE 2024) recommend diagnosing OA based on symptoms and signs, not relying solely on imaging findings.

Prognosis

Knee OA is a long-term condition, but with proper management, symptoms can be well controlled. Many people maintain good activity levels for years.

OA doesn’t always rapidly deteriorate — many live with knee OA for years with manageable symptoms.

Factors associated with a worse prognosis include higher body weight, knee alignment issues (varus/valgus), heavier joint loading, poor muscle strength, and more advanced imaging changes.

Guidelines consistently recommend education, exercise (especially strengthening), and weight management as the core elements of care.

There is no cure that reverses cartilage damage completely, but symptom control and preserving function are realistic and achievable goals.

The good news is that regular exercise, healthy weight, and early physiotherapy intervention can significantly delay progression and reduce pain.

Best Exercise and Why

One of the most important parts of managing knee OA — and this is backed by current research and guideline consensus — is exercise. Let’s break down the best types and why they work.

What Kind of Exercise?

• Strengthening: Focus on the quadriceps (front thigh) and gluteal (buttock) muscles. Stronger muscles offload the knee, improve joint stability, and distribute load more evenly.

• Movement and load: The knee cartilage acts like a sponge. When you compress and decompress the joint during movement, joint fluid flows in and out, delivering nutrients. Movement literally helps the joint “feed” itself.

• Aerobic / low-impact activity: Walking, cycling, or swimming help maintain cardiovascular fitness, support weight control, and keep joints mobile without excessive stress.

• Progressive loading: Start gently and build up. Gradual loading helps the knee adapt, whereas total rest can lead to weakness and stiffness.

  
  

Why Does It Work?

• Strong muscles reduce joint pressure and pain.

• Movement promotes healthy joint fluid circulation and cartilage nourishment.

• Exercise improves everyday function — like standing, walking, or climbing stairs — and enhances quality of life.

• Maintaining activity also helps with weight control, further reducing mechanical stress on the knee.

  
  

Practical Examples

• Seated knee extensions: Straighten the knee, hold 2–3 seconds, and lower slowly.

• Glute bridges: Lift hips to form a line from shoulders to knees, hold briefly, then lower.

• Sit-to-stands / mini-squats: Build strength and control in functional positions.

• Low-impact cardio: Walking, cycling, or pool exercises 15–30 minutes most days.

• Stretching: Hamstring and calf stretches to maintain flexibility.

  
  

Important Tips

• Mild discomfort is normal; avoid sharp or lasting pain.

• Consistency matters more than intensity.

• Work with a physiotherapist to tailor your plan.

• Include everyday movement — not just “gym” sessions.

  
  

What Do the Guidelines Say?

Leading guidelines (OARSI 2019, ACR 2020, NICE 2024) all identify education, exercise, and weight management as the foundation of OA care. For knee OA, the best approach combines muscle strengthening, movement, and low-impact aerobic exercise to reduce pain and improve joint health.

Recommended Supportive Solutions

Managing OA effectively often means combining symptom relief and functional support for long-term joint comfort.

🔹 Symptomatic Relief: Corticosteroid Injections

During flare-ups — when the knee feels swollen, “angry,” or painful — steroid injections may be considered. They act as powerful anti-inflammatories, calming local irritation and reducing swelling. Evidence shows short-term pain relief and improved mobility lasting several weeks. They’re best used occasionally and always alongside exercise and physiotherapy.

! Steroids aren’t a cure, but they can help you move better so you can keep strengthening and staying active.

🔹 Functional Support: Osenil® (Hyaluronic Acid)

Osenil® is a research-supported joint lubricant and cushioning treatment designed to support long-term knee comfort and function. It contains high-molecular-weight hyaluronic acid, a natural component of joint fluid that helps:

• Restore lubrication and shock absorption

• Promote smoother joint movement

• Reduce mechanical friction inside the knee

Clinical research shows that hyaluronic acid injections like Osenil® can offer longer-term improvements in stiffness, function, and pain compared to placebo — particularly in mild to moderate OA when maintaining activity is the goal.

In short:

• Steroid injections calm an “angry knee” during flares.

• Osenil® helps keep the joint smooth and mobile over time.

Always discuss these options with your physiotherapist or healthcare provider to determine what’s most appropriate for your symptoms and stage.

Common Misconceptions and Myths

Myth 1: “It’s just wear and tear — nothing can be done.” 

✅ Reality: OA is highly manageable. Exercise, education, and weight control can change its course and delay progression.

Myth 2: “You must rest completely or you’ll make it worse.” 

✅ Reality: Too much rest weakens muscles and stiffens joints. Controlled activity protects your knees.

Myth 3: “If it’s on the X-ray, it will keep getting worse.” 

✅ Reality: Imaging doesn’t always match symptoms. Many people maintain good mobility for years.

Myth 4: “Medications or injections replace exercise.”

✅ Reality: These support comfort but do not replace the need for regular movement and muscle strength.

Myth 5: “Pain means damage.” 

✅ Reality: Mild discomfort is part of rebuilding strength. Persistent or severe pain should be reviewed, but gentle movement is safe and helpful.

Key Takeaway

Knee OA is common — but it’s manageable.

With the right combination of activity, muscle strength, and supportive treatments, you can stay mobile, reduce pain, and maintain your quality of life.

Move smart. Stay strong. Stay supported.

For more information about physiotherapy-based OA management or joint-lubricating support such as Osenil®, speak with your local physiotherapist or healthcare provider.