ACL Injury – Symptoms and Causes
Overview
An ACL injury occurs when the anterior cruciate ligament in the knee tears or sprains. This ligament helps connect the thigh bone to the shinbone.
These injuries typically happen during activities involving quick direction changes, sudden stops, or jumping—common in sports like soccer, basketball, football, and skiing.
When an ACL tears, many people hear or feel a distinctive “pop” in their knee. Common symptoms include:
- Swelling around the knee
- Feelings of instability
- Pain when putting weight on the leg
Treatment options vary based on the injury’s severity.
Some patients may need only rest and specialized exercises to rebuild strength and stability. Others might require surgery to replace the damaged ligament, followed by rehabilitation therapy.
What Your Body Shows When You Hurt Your ACL
When you hurt your ACL, your body will show several clear signs. You might hear a loud pop or feel a popping feeling in your knee.
The pain can be very bad, making it hard to keep doing what you were doing. Your knee may swell quickly. You might not be able to move your knee as much as usual.
When you put weight on your leg, your knee might feel unstable or like it’s going to give out.
When You Should Get Medical Help
Don’t wait to get help if you hurt your knee and notice any ACL injury signs. Go to a doctor right away.
Your knee is complex, with many parts working together, including bones, ligaments, and tendons. Getting checked quickly helps doctors figure out how bad the injury is. This leads to better treatment and can improve your recovery.
Causes
The ACL (anterior cruciate ligament) is a strong band of tissue that joins your thighbone to your shinbone that helps keep your knee stable.
ACL injuries happen when this important ligament gets damaged.
Several activities can lead to ACL injuries, especially during sports. These include:
- Making sudden stops
- Changing direction quickly while running
- Pivoting with your foot planted firmly on the ground
- Landing incorrectly after jumping
- Taking a direct hit to the knee
- Colliding with another person (like in a tackle)
When an ACL injury occurs, the ligament may be partially or completely torn. Sometimes, a minor injury might only stretch the ligament without tearing it.
Sports that involve jumping, pivoting, and sudden movements put athletes at higher risk for these injuries.
Risk Factors
Several factors can raise your chance of getting an ACL injury:
- Gender: Women face a higher risk, possibly due to physical differences and hormonal effects.
- Sports: Soccer, football, basketball, gymnastics, and downhill skiing have high injury rates.
- Physical condition: Poor fitness increases the risk.
- Movement patterns: Moving knees inward during squats can lead to injury.
- Equipment issues: Ill-fitting shoes or poorly maintained equipment (like loose ski bindings).
- Playing surface: Artificial turf poses a greater risk than natural grass.
Women athletes have a higher risk of ACL injuries.
Complications
ACL injuries increase the chance of knee osteoarthritis later in life. Surgery to rebuild the ligament doesn’t always prevent this problem.
Several elements can affect arthritis risk:
- Injury severity – more damage means higher risk.
- Associated knee injuries – damage to other parts of the knee joint.
- Activity level after treatment.
Even with proper treatment, the joint may develop arthritis over time. This is why proper rehabilitation and following medical advice are important parts of recovery.
Ways to Avoid Injuries
Choosing the right equipment for your sport is important for safety.
Wear proper shoes and padding when playing sports. For downhill skiing, make sure a trained professional adjusts your ski bindings correctly. This ensures your skis will release properly if you fall, which can prevent injuries.
Research shows that knee braces don’t seem to prevent ACL injuries. They also don’t lower the risk of getting hurt again after surgery.
Good training can reduce your risk of getting hurt. A sports doctor, physical therapist, or athletic trainer can help you learn safe movements. They can watch you exercise and suggest improvements to protect your knees.
Helpful training programs include:
- Core-strengthening exercises that focus on the hips, pelvis, and lower abdomen.
- Leg muscle exercises, especially for hamstrings, to create balanced strength.
- Proper jumping technique with safe landing positions.
- Movement training for pivoting and cutting safely.
