🦵 Stiff Knee After Injury or Surgery?

What You Can Do

If your knee feels stiff, heavy, or difficult to bend or straighten, you’re not alone. Knee stiffness is one of the most common issues after injury or surgery —that our physiotherapists at BOOST PHYSIO help people recover from. Knee stiffness is also one of the most important to treat early.

At BOOST PHYSIO, we regularly help patients recovering from ligament sprains, meniscus tears, knee replacements and arthroscopy surgery (ACL reconstructions) who struggle with reduced movement, pain and swelling.
Here’s what causes stiffness, why it matters, and how you can get your movement back.

Why Does the Knee Become Stiff?

After any knee injury or surgery, your body naturally responds with swelling and inflammation. This is part of the healing process — but it can quickly limit movement.
Several factors contribute to stiffness:

  • Swelling: Excess fluid inside the joint capsule restricts motion and makes bending or straightening uncomfortable.

  • Pain: The body instinctively avoids painful movement, which leads to further tightness and weakness.

  • Inflammation: Causes tissues to become thickened and less elastic.

  • Muscle guarding: The muscles around the knee tighten up to protect the joint but often stay switched on too long.

  • Scar tissue formation: Following surgery or injury, adhesions can form, physically limiting range of motion.

If stiffness isn’t managed early, it can persist long after pain improves — affecting your recovery, confidence, and independence.

Why Full Movement Matters

A stiff knee can make even simple activities difficult:

  • Getting in or out of a car

  • Putting on shoes and socks

  • Climbing stairs or kneeling

  • Sitting comfortably for long periods

Both full extension (straightening) and full flexion (bending) are essential for normal walking and function.
Without full extension, your leg can’t fully bear weight, causing limping and quadriceps weakness.
Without full flexion, everyday activities like driving, kneeling, or squatting remain limited.

Hands-On Physiotherapy to Restore Movement

The first 6–12 weeks after an injury or operation are critical to regain range of motion and prevent long-term restriction.
Our team uses a combination of evidence-based, hands-on treatment and guided rehabilitation to help you recover quickly and safely.

Our treatment options may include:

  • 👐 Joint mobilisations and myofascial release to ease tight tissues and improve flexibility.

  • 🔁 Movement-with-mobilisation (MWM) and hold–relax PNF stretching to retrain safe movement patterns.

  • 💪 Targeted strengthening and exercise rehabilitation to support mobility gains.

  • 💧 Hydrotherapy for gentle range-of-motion work in a low-impact environment.

  • ⚡ Electrotherapy or NMES to support muscle activation and reduce pain.

With consistent treatment and home exercise, most patients regain movement.

What You Can Do at Home to Regain Knee Movement

Your progress between physiotherapy sessions matters just as much as the treatment itself. Here are practical home strategies our physios recommend:

Early-stage home exercises

  • Regular movement: Gently bend and straighten your knee several times every hour to prevent stiffness.
  • Heel slides: Lying down, slide your heel towards your bottom, bending as far as comfortable, then straighten again.
  • Quad activation: Tighten your thigh muscle by pressing the back of your knee into the bed for 5 seconds, then relax.
  • Knee hangs: Rest your heel on a rolled towel or cushion and let gravity help the knee fully straighten.
  • Swelling control: Elevate your leg and use ice for 10–15 minutes after exercises to reduce inflammation.

Progressions as stiffness improves

  • Stationary cycling: Start with gentle half-pedals, gradually increasing the range as movement returns.
  • Wall slides or supported mini-squats: Build strength and control through partial movement.
  • Calf and hamstring stretches: Keep these muscles flexible to support full range of motion.
  • Warm compress or gentle bath mobility: Warmth relaxes tissues before stretching or exercising.

Even five minutes of focused movement, 3–4 times per day, can make a big difference. Consistency, patience and proper technique are key.

When to Seek Professional Help

If your stiffness lasts more than a few days, or your knee won’t fully straighten or bend, it’s time for a professional assessment.

Early physiotherapy can prevent long-term problems such as:

  • Joint capsule tightness or scar tissue adhesions
  • Persistent swelling or muscle weakness
  • Abnormal walking patterns or knee pain

Your Best Recovery – Guaranteed

At BOOST PHYSIO, we specialise in helping patients regain pain-free knee movement through expert same-day private physiotherapy near you.

Our 10 London and Hertfordshire clinics offer fast access, hands-on care and tailored rehabilitation — so you can get back to doing what you love.

📅 Book your appointment today: https://boostphysio.janeapp.co.uk

🏥 Expert same-day private physiotherapy near me at BOOST PHYSIO.