Knee pain can creep in slowly or hit you all at once. It might show up after a long run, a tough gym session, or even just walking up and down stairs. For some people, it lingers for weeks. For others, it keeps coming back every time they try to train or stay active.
The knee is a hardworking joint. It absorbs force, stabilises your body, and supports almost every lower-body movement. When something is not working properly, pain is often the first sign.
Summary: The most common causes of knee pain include tendon irritation, patellofemoral pain, ligament sprains, meniscus injuries, and osteoarthritis. While mild pain may settle with rest, persistent, worsening, or recurring symptoms should be assessed by a physiotherapist. Early treatment can reduce recovery time and prevent long-term issues.
1. Patellofemoral pain syndrome
Often described as pain around or behind the kneecap, this condition is common in runners, gym-goers, and people who sit for long periods.
You may notice:
- Pain when walking downstairs
- Discomfort during squats or lunges
- Aching after sitting with bent knees
It usually develops due to poor tracking of the kneecap, muscle imbalances, or overload. Strengthening and movement correction are key parts of treatment.
2. Tendon irritation
The patellar tendon connects your kneecap to your shin bone. When overloaded, it can become irritated and painful.
Common in:
- Jumping sports
- High-volume training
- Sudden increases in activity
Pain is typically felt just below the kneecap and worsens with jumping, sprinting, or heavy leg exercises. Proper load management and progressive strengthening are essential for recovery.
3. Meniscus injuries
The meniscus is a piece of cartilage that cushions the knee joint. It can be injured during twisting movements or deep squatting.
Symptoms may include:
- Locking or catching
- Swelling
- Sharp pain with rotation
- Reduced range of motion
Not all meniscus injuries require surgery. Many respond well to structured rehabilitation.
4. Ligament sprains
Ligaments stabilise the knee. Sudden changes in direction, awkward landings, or direct impact can cause sprains.
You may experience:
- Instability
- Swelling
- Pain with weight bearing
- A popping sensation at the time of injury
Early assessment is important to determine the severity and guide appropriate rehabilitation.
5. Osteoarthritis
Knee osteoarthritis becomes more common with age but can also affect younger individuals, especially after a previous injury.
Symptoms often include:
- Stiffness in the morning
- Swelling after activity
- Gradual increase in pain
- Reduced mobility
Contrary to common belief, movement and strength training are some of the most effective ways to manage symptoms.
When should you see a physio?
Some knee pain improves with short-term rest and reduced activity. However, you should consider booking an appointment if:
- Pain lasts longer than one to two weeks
- Swelling persists
- The knee feels unstable
- Pain keeps returning when you resume activity
- It is affecting work, sport, or sleep
The longer you push through pain without addressing the cause, the more compensation patterns can develop.
What to expect in a physiotherapy assessment
A physiotherapist will:
- Take a detailed history of your symptoms
- Assess strength, mobility, and movement patterns
- Identify contributing factors such as muscle weakness or poor mechanics
- Provide a clear diagnosis and recovery plan
Treatment may include hands-on therapy, progressive strengthening, mobility work, and guidance on activity modification.
Why early treatment matters
Ignoring knee pain can lead to:
- Chronic symptoms
- Reduced performance
- Secondary issues in the hips or ankles
- Longer recovery timelines
Addressing the root causes of knee pain early improves outcomes and helps you return to activity safely.
Key takeaways
- The most common causes of knee pain include tendon issues, meniscus injuries, ligament sprains, patellofemoral pain, and osteoarthritis
- Persistent or recurring pain should not be ignored
- Early physiotherapy reduces recovery time and prevents long-term complications
- Strength and movement correction are central to most knee rehabilitation programs
Ready to move without knee pain?
At Rebound Health, we provide industry-leading care to help you feel and function at your best. Our team works across physiotherapy, nutrition, and performance to deliver measurable, lasting results.
If knee pain is limiting your training or daily life, book an assessment and take the first step towards stronger, more confident movement.