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Three Common Knee Culprits: How They Differ
Knee pain is a broad term. To understand your injury, we need to look at where it hurts and how the pain started.
| Injury | Typical Symptoms | Cause |
|---|---|---|
| Meniscus Injury | Sharp pain during twisting, locking, delayed swelling. | Twisting force or long-term wear. |
| ACL Injury | Severe swelling (immediate), feeling of instability ("giving way"). | Acute trauma, often jumps or sudden stops. |
| Runner's Knee | Aching pain on the outside of the knee, often after a certain distance. | Overuse of the iliotibial band. |
1. Meniscus Injuries: The Worn or Torn Shock Absorber
The meniscus acts as the knee's shock absorber. These injuries are often divided into two categories:
- Acute Twisting: Typical in sports like padel or football. It often feels like a sharp sting and can be followed by the knee "locking".
- Degenerative Injury (Wear): For experienced athletes, the meniscus can become brittle over time. No specific trauma is needed; a deep squat might be enough to cause a tear in worn tissue.
2. ACL Injury: When Stability Vanishes
The anterior cruciate ligament (ACL) is vital for knee stability during forward motion and rotation.
Symptoms: A "popping" sound is often heard at the moment of injury. Unlike meniscus injuries, the knee usually swells significantly within an hour.
The Feeling: The most typical description is "giving way" – a sensation that the lower leg and thigh aren't connected.
3. Runner's Knee: The Classic Overuse
This isn't about something breaking, but a tendon rubbing against bone.
Symptoms: A distinct, aching pain on the outside of the knee that creeps up after a few kilometers.
Cause: Often due to a combination of weak hip muscles and increasing training intensity too quickly.
"Good" vs. "Bad" Pain – Know Your Body
Good Pain (Reaction Pain): An ache during training that doesn't increase progressively and fades by the next day.
Bad Pain (Warning Pain): Sharp stabbing pain, night pain, locking of the joint, or severe swelling.
From Self-Diagnosis to Confirmed Diagnosis
When rest and light rehab don't help, it's time for a professional assessment:
- Physiotherapist: Performs clinical tests to check ligaments and menisci.
- Doctor/Orthopedist: Consulted for structural damage or surgical needs.
- MRI: The gold standard for visualizing soft tissues like the meniscus and ACL.