A to Z: Anterior Cruciate Ligament (ACL) Injuries

A to Z: Anterior Cruciate Ligament (ACL) Injuries

A to Z: Anterior Cruciate Ligament Injuries

May also be called: ACL Injury; ACL Tear

An ACL injury is a tear in one of the ligaments in the knee.

More to Know

The ACL, one of the main ligaments in the knee joint, is located behind the kneecap. It keeps the shinbone in place and prevents it from moving too far forward, away from the knee and thighbone. The ACL also keeps the knee stable when rotating.

ACL injuries can be painful and lead someone to feel wobbly and have trouble walking. Kids and teens with suspected ACL injuries should stop all activity, keep the area iced and elevated, and see a doctor as soon as possible.

ACL injuries are usually sports related. Sports like soccer, baseball, or basketball that feature swift, abrupt movements are most likely to lead to ACL tears. The ACL also can tear when someone jumps or lands with the knees straight or "locked" instead of flexed or slightly bent.

torn ACL illustration

Keep in Mind

Girls are 8 to 10 times more likely to tear an ACL than boys are. The ACL won't heal on its own, but how doctors treat an injury depends on how severe it is and the child's age.

Following proper playing techniques, wearing protective equipment, doing strength training to keep surrounding muscles strong, and warming up with dynamic stretching are key to protecting against injury.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.





Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

© 1995-2014 The Nemours Foundation/KidsHealth. All rights reserved.





Bookmark and Share

Related Resources
OrganizationAmerican Academy of Orthopaedic Surgeons (AAOS) The AAOS provides information for the public on sports safety, and bone, joint, muscle, ligament and tendon injuries or conditions.
OrganizationAmerican Academy of Pediatrics (AAP) The AAP is committed to the health and well-being of infants, adolescents, and young adults. The website offers news articles and tips on health for families.
OrganizationAmerican Physical Therapy Association This organization provides information on physical therapy, from therapists in each state to current research.
OrganizationNational Athletic Trainers' Association This site contains information on certified athletic trainers and tips on preventing and healing sports injuries.
OrganizationAmerican Academy of Family Physicians This site, operated by the American Academy of Family Physicians (AAFP), provides information on family physicians and health care, a directory of family physicians, and resources on health conditions.
Related Articles
Jumper's Knee Jumper's knee is an inflammation or injury of the patellar tendon. Although it can seem minor, it's actually a serious condition that can get worse over time and ultimately require surgery if not treated.
Jumper's Knee (Patellar Tendonitis) Jumper's knee is an inflammation or injury of the patellar tendon. Although it can seem minor, it's actually a serious condition that can get worse over time and ultimately require surgery if not treated.
Strains and Sprains Are a Pain What's a sprain? What's a strain? Find out in this article for kids.
Medial Collateral Ligament (MCL) Injuries MCL injuries - which are common in active and athletic kids - happen when excessive pressure is put on the knee joint, resulting in a torn ligament.
Dealing With Sports Injuries You practiced hard and made sure you wore protective gear, but you still got hurt. Read this article to find out how to take care of sports injuries - and how to avoid getting them.
Preventing Children's Sports Injuries Participation in sports can teach kids sportsmanship and discipline. But sports also carry the potential for injury. Here's how to protect your kids.
Bones, Muscles, and Joints Without bones, muscles, and joints, we couldn't stand, walk, run, or even sit. The musculoskeletal system supports our bodies, protects our organs from injury, and enables movement.
Anterior Cruciate Ligament (ACL) Injuries ACL injuries - which are common in active and athletic kids - happen when excessive pressure is put on the knee joint, resulting in a torn ligament.
Knee Injuries Knee injuries are common among young athletes. Learn about causes, treatments, and prevention.
Anterior Cruciate Ligament (ACL) Injuries ACL injuries - which are common in active and athletic people - happen when excessive pressure is put on the knee joint, resulting in a torn ligament.
Medial Collateral Ligament (MCL) Injuries MCL injuries - which are common in active and athletic teens - happen when excessive pressure is put on the knee joint, causing a torn ligament.
Knee Injuries Healthy knees are needed for many activities and sports and getting hurt can mean some time sitting on the sidelines.
Bones, Muscles, and Joints Our bones, muscles, and joints form our musculoskeletal system and enable us to do everyday physical activities.
iGrow iGrow
Sign up for our parent enewsletter