ACL Injury

Causes, Symptoms and Treatment

Overview of ACL Injuries

Tearing/spraining of the anterior cruciate ligament (ACL) is the injury of an important ligament inside the knee. This is one of two ligaments inside the knee capsule that connect the upper leg bone (femur) to the lower leg bone (tibia). Theses injuries are common with activities and sports that involve dynamic movements such as jumping,  landing, running and changing directions. Slips and falls also can lead to ACL injury.

After an ACL injury your knee may be unstable, swell, and hurt too much to stand or walk. Treatments can include protective bracing, rest, ice, compression, elevation, myofascial release, joint mobilizations, and rehabilitative exercises to restore range of motion, mobility, strength, and stability. Depending on the severity of your injury, surgical intervention may be needed to repair or replace the torn ligament.

ACL injury risk can be decreased with proper training programs that emphasize joint mobility and stability. Building posterior chain (hamstrings, buttock, and back muscles) strength, core stability, hip stability, hip mobility, technique training on jumping, pivoting and cutting help decrease ACL injury risk.

Common Causes of ACL Injury

ACL Injuries are most often seen in people who participate in activities that cause them to move and stop rapidly or change direction rapidly.  These activities put stress on the knee and sometimes cause injury.  Slips, falls and abnormal/unexpected movements can also cause ACL injury depending on the pre-existing risk factors.

Commonly Associated Activities

  • Football
  • Basketball
  • Soccer
  • Skiing
  • Other activities that involve sudden changes in direction, twisting, jumping and sudden stops

Common Risk Factors for ACL Injury

  • Wide hips leading to knees leaning towards each other or “knock kneed”
  • Post puberty women are at a higher risk due to anatomical influences
  • Poor physical conditioning
  • Engaging in high risk sports and activities

Symptoms Associated with ACL Injury

Unfortunately the symptoms of ACL Injury are usually pronounced and immediate.  Depending on the severity, most people know when they have done damage to their ACL because of the intense pain and swelling that follows.  This pain and swelling also frequently leads to temporary loss of motion in the knee and a lack of stability (sometimes even to the point of inability to walk).  Some people may also experience the sensation of “popping” in the knee and may even hear an audible “pop” come form the knee. If you experience any of these symptoms after an injury, make sure that you get evaluated as soon as possible.

Commonly Associated Symptoms

  • Possible audible popping sound or sensation deep inside the knee
  • Swelling
  • Stiffness leading to a loss of range of motion
  • Severe pain
  • Inability to continue playing or working
  • Knee instability, possibly even to the point of being unable to walk
  • Muscle spasms

Treatment and Prevention of ACL Injuries

Most of the common causes of ACL Injury are preventable.  When seeking treatment for an ACL injury it is important to also work on methods of re-injury prevention.  Every persons body is different and body types, anatomical differences, gender and other factors may contribute to your risk for this type of injury.  Individual assessment it an important tool in coming up with ways to prevent ACL injury.  This assessment may include technique analysis and movement screening, strengthening exercises, or training to improve strength in key areas of the body.  

Common Treatments for ACL Injury

  • Protective bracing – helps improve stability of the joint to add in weight bearing, improve ability to walk and decrease future injury from the knee “giving out”
  • Rest – limits pressure and stress on the injured knee
  • Ice – helps to decrease pain and swelling/inflammation
  • Compression – limits swelling/inflammation
  • Elevation – improves drainage of swelling/inflammation in the knee
  • Myofascial release – helps improve pain free range of motion by decreasing myofibrotic adhesions (scar tissue) and muscle spasm
  • Joint mobilizations – improves range of motion and circulation in the joint
  • Rehabilitative exercises – these focus on restoring range of motion, mobility, strength, and stability
  • Surgical intervention – depending on severity, may be needed to replace the torn ligament and then will be followed by rehabilitatio