Brian Davis, MD, on ACL injury risks factors and prevention tips

Whether you are a professional athlete, a weekend warrior or an active individual who enjoys recreational sports, a torn or sprained anterior cruciate ligament (ACL) in your knee can happen, putting a damper on your physical activity.

“ACL injury is usually a twisting episode of your knee during changes in direction, jumping or landing, or a direct blow to the knee,” stated Brian Davis, MD, of BoulderCentre for Orthopedics, who is dual fellowship trained in orthopedic sports medicine and shoulder and elbow surgery. “In Colorado, ACL ski injuries are common, because the ski binding doesn't release, putting a huge amount of force of rotation on the knee and that can cause your ACL to give out.”

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Watch Preventing and treating ACL injury

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Symptoms of ACL injury

Dr. Davis said that many patients report experiencing the following symptoms from an ACL tear:

• Pop/snap felt in the knee
• Knee gives way and feels unstable
• Severe pain
• Feelings of instability when walking
• Immediate swelling (typically within 1 hour)

“You usually get immediate swelling with the injury, because there is a blood vessel that goes across the ACL. When you rupture the ACL that blood vessel also gets ruptured, and it fills the knee with blood,” Dr. Davis explained.

Risk factors

Non-modifiable

Nonmodifiable risk factors for an ACL injury are those that cannot be controlled. These include:

• Female gender - “If you're female,” stated Dr. Davis, “you are at a much higher risk – a four-to-six times higher risk than a male to have an ACL injury.” He then explained the reasons females are more at risk:
  • They have a smaller notch for the ACL “to live in, which restricts how much motion you can have before it ruptures.”
  • They tend to have “more of a knock-kneed alignment to their knee, which puts them in a position where it's more likely to rupture.”
  • They tend to be quad-muscle dominant, which means “when they land from a jump they're more likely to go into a knock-knee position, putting them at risk for an injury.”
  • They have hormonal differences. “Estrogen is thought to stretch out ligaments. With the higher amount of estrogen, females are more likely to have a stretchy ACL.”
     
• Tibial plateau anatomy (tibial slope) – If the shape of your shin bone is sloped that puts you at a higher risk.
• Family history – If you have a family member who had an ACL rupture you are at two times higher risk.
• Ligamentous laxity – If you're double-jointed you may be at higher risk for an ACL injury.
• Age 15 - 25 years old – If you're young and very active, you're in the highest risk category.

Modifiable

Dr. Davis shared things that you can change and lessen your risk for an ACL injury include:

• Landing mechanics – You can change how you land when you come down from a jump.
• Footwear – “If you're using very long cleats, you're more likely to have a foot that's planted and doesn't turn, which can put you at risk,”.
• Playing surface – “Researchers have discovered that athletes playing at lower levels experienced ACL tears 1.6 times more often on turf than they did on the grass.”
• Sport - “If you’re involved in a high-risk sport, such as soccer, volleyball or basketball, then you're more likely to sustain an injury. You're jumping to land in a position that puts you at risk.”

ACL injury prevention

All successful ACL injury prevention recommendations share a common focus: improving flexibility, strength (particularly of the core, hips and legs), balance, agility, and your ability to jump and land safely.

Land correctly

Dr. Davis said, “Many ACL injuries result from landing incorrectly after a jump.” He added the most important things to keep in mind are to:

• Land evenly on both feet
• Point toes straight forward
• Keep your knees over your toes
• Bend from the hips and knees when landing
• Keep knees shoulder width apart during landing
• Never let your knees collapse inward

Strengthen your core muscles

Strengthening the muscles in your back and abdomen can help with balance and improve stability when you need to change directions quickly.

Strengthen your leg muscles

Since weak hamstrings often play a role in many ACL injuries, Dr. Davis said exercises that target those muscles can be especially helpful. Squats and lunges are just a couple of exercises that work the quadriceps and build strength in your legs.

“Take about 20 to 30 minutes multiple times per week to help strengthen the structures around the knee,” Dr. Davis recommended.

A physical therapist can teach you how to perform core-strengthening and leg-strengthening exercises correctly to help prevent ACL injury. 

Also, check out the following exercises from FIFA to minimize your risk and possibly prevent an ACL injury.

To make an appointment with Brian Davis, MD, of BoulderCentre for Orthopedics, call (303) 449-2730.