Whether you’re a casual skier or elite athlete, you’re at risk of injuring your anterior cruciate ligament (ACL). If you’re a woman, you’re at even greater risk. But there are steps you can take to prevent ACL injuries.
"Among athletes, women are more than twice as likely to have an ACL injury than men,” says Lafi Khalil, M.D., a sports medicine orthopedic surgeon at Henry Ford Health. “Having an ACL-deficient knee can put you at greater risk for having further injuries to the knee cartilage, meniscus and other ligaments. That’s why it is important to prevent these injuries and follow your treatment plan if injured.”
What Is An ACL Injury?
The ACL is one of the four major ligaments that support the knee. It is a strong band of tissue that resides in the center of the knee and connects your thigh bone (femur) to your shin bone (tibia).
“The ACL prevents the shin bone from shifting or pivoting excessively in relation to the thigh bone, essentially stabilizing the knee during pivoting and cutting activities,” says Dr. Khalil. “An ACL injury usually occurs without contact when you turn suddenly while running or land off-balance on one leg, but it can also occur in contact injuries. These actions overload the knee joint and cause the ACL to tear.”
In the United States, around 100,000 people sustain an ACL injury each year. Anyone can experience an ACL injury, although athletes participating in sports like football, basketball, soccer, skiing and gymnastics are at highest risk. Seek immediate care if you have any of these signs of an ACL injury:
- An audible “pop” in the knee
- Intense knee pain and rapid onset swelling (within hours)
- Loss of range of motion
- An unstable feeling or locking of your knee
The most common treatment for ACL injuries in athletes is surgery followed by physical therapy. After treatment, approximately 90% of athletes can expect to return to normal activities in nine to 12 months. However, peak athletic performance can take up to two years and only 70% of athletes achieve their prior level of performance.
The Link Between ACL Injuries and Women
According to Dr. Khalil, the differences in pelvic and lower extremity anatomy, neuromuscular control, biomechanics and hormonal influences are all factors associated with increased ACL injury risks in females.
“The multifactorial influences on ACL injury risk have been a hot topic of research in both males and females,” he says. “As a result, significant advancements have been made in injury prevention programs, neuromuscular training and athlete education.”
Dr. Khalil says there are many theories about a female’s increased risk for ACL injuries compared to males, including:
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- Anatomical differences: Studies have investigated the geometry of the knee, finding associations between ACL tears and smaller “notches” in the center of the knee (where the ACL resides) as well as increased “slope” on the shin bone where it attaches. While it is an area requiring further research, these anatomic differences may affect females more than males, as studies show reduced stability in females when these factors are present. In addition, the wider pelvis in females results in a relatively greater angle between the hips and knees, theoretically placing the knees in more vulnerable positions when jumping and landing.
- Differences in neuromuscular control: In studies evaluating muscle activation patterns, women demonstrate imbalances between the quadriceps and hamstring muscles, with quadriceps muscles overpowering the hamstring muscles, resulting in an increased anterior (forward) pull on the shin bone, placing the ACL at greater risk of injury. In addition, weaker hip abduction strength (muscles located on the outer thighs and hips), core stability, knees collapsing inward when performing athletic activities, and a more upright posture upon landing may all contribute to increased ACL injury risk due to biomechanics when jumping/landing.
- Ligament laxity: Men and women have different laxity, or flexibility, in their ligaments. Studies show females have greater knee joint laxity, which may reduce stability in the knee. Also, studies show that fluctuating hormone levels during menstrual cycles may be correlated to fluctuating ACL laxity. Some studies have correlated greater injury risk in the midcycle (ovulatory phase), but this is an ongoing area of research that is not fully understood yet.
Steps To Prevent ACL Injuries
“The best way to prevent ACL injuries is to begin and maintain regular conditioning exercises at an early age,” says Dr. Khalil. “Focus on addressing strength imbalances, including neuromuscular training for proper biomechanics. The more frequently you train to safely perform activities specific to your sport, the lower your risk for injury.”
Consult with a sports medicine specialist, physical therapist or athletic trainer to develop a training routine to prevent ACL and other injuries. Your training program should include exercises that:
- Strengthen the muscles that support your knees, hips and core: Add strength training to build up your core, hip abductors, calves, hamstrings and quadriceps muscles. These muscles help stabilize your knee as you perform pivoting and cutting activities. Strengthening these muscle groups evenly can lower your risk for ACL injury.
- Improve overall neuromuscular control: Focus on adding neuromuscular exercises that train your nerves and muscles to react and communicate. For example, you can stand on one leg to work on your balance. You can watch yourself in landing or squatting positions to adjust your mechanics, or perform supervised training drills specific to ensure your form does not break down when fatigue sets in. And core exercises can strengthen the muscles that support your abdomen and back, along with improving your posture. These moves can strengthen your joints and help you learn appropriate balance and technique.
“Exercise really is the best medicine,” says Dr. Khalil. “It can improve your balance and agility as you participate in a sport or prevent injury as you move through your daily activities. Consider adding these preventative strategies into your athletic training to reduce your risk for injury.”
Reviewed by Lafi Khalil, M.D., a sports medicine orthopedic surgeon who sees patients at Henry Ford Orthopedics – Chesterfield and Washington Twp.
