Preventing ACL injury

Preventing ACL injury

As teens return to high school and start practicing varsity sports, parents sit on the sidelines and hope it’s not their child that has a serious injury like an ACL tear. Which types of athletes are at a higher risk for ACL injuries? What can athletes do to prevent them?

A brief aside: This post focuses on how to prevent non-contact ACL injuries, defined by Lee Couret, a Physiquality network physical therapist and owner of Southshore Physical Therapy in Louisiana, as an injury without any external force applied to the limb or joint.

All of our experts agreed that female athletes were at a much higher risk for non-contact ACL injuries. Robyn Smith, a physical therapist at The Center for Physical Rehabilitation (a Physiquality network physical therapy clinic) and lecturer on ACL injuries in female athletes, says that female athletes sustain ACL injuries “anywhere from 1.5 to 4.6 times more often than males in the same sport.” A variety of intrinsic factors cause these higher rates of injury, including alignment, anatomical differences, a smaller and thinner ACL, and coordination.

Sports like basketball, soccer, volleyball and football have a higher risk of ACL injury.The sport being played is also important to consider. Lee notes that the types of movement that lead to non-contact injuries often involve quick stops, cutting movements (when intercepting passes), and sudden changes in direction. So sports that involve such movement, like basketball, soccer, volleyball and football, will put players at a higher risk for ACL injury.

Susan Sigward, a physical therapist and a coordinator of the ACL Project Prevent at the University of Southern California, had been working as a physical therapist and athletic trainer with young athletes and was getting tired of seeing so many girls going into surgery after these non-contact ACL tears. Susan began researching why these injuries occurred; she wanted to know what types of exercises reduced injury and why. As part of ACL Project Prevent, Susan analyzed what was going on biomechanically with these athletes, essentially asking, “Do females perform athletic tasks differently than males?” She used special software to record girls’ movement during soccer before and after an exercise program developed by the Santa Monica Orthopaedic Group and implemented by CATZ Physical Therapy Institute, a Pasadena-based (and Physiquality member and partner) physical therapy clinic and athletic training facility.

While Susan and her team at ACL Project Prevent are still analyzing the data they gathered on over 200 female athletes, a few points have become clear as they’ve been doing the program:

  • If athletes do certain exercises before their practices and games, many of them will reduce their chances of ACL injury. The question is how well they will stick to the program and continue to do the exercises when they have not been injured or feel better after a previous injury (i.e., if I’m not in pain or suffering an injury, I must be strong enough to no longer need to do the exercises).
  • Outside of these preventive exercises, in order to be a competitive athlete, you need to be able to control your body while running around. This means that you’ll need good leg and trunk strength, strong hip muscles, good power and strength while moving quickly, and agility.
  • The biggest risk for tearing your ACL is having already torn your ACL. Was the athlete already at risk? Or did she return to activity too quickly? The answer is unclear, but it shows that if athletes have already injured their ACLs, they need to exercise precaution and listen carefully to their orthopedic surgeons and physical therapists as to when they can return to their sports.
  • Susan’s main point is that girls need to learn how to condition their bodies year-round, not just when they’re doing their particular sport. This cross-training will build general strength and agility, as well as the areas that will protect their ACL. She maintains that “a good foundation of strength is the best way to avoid injury.”

Be sure to use proper form during squats.Joyce Klee, a physical therapist and co-owner at Physiquality member Clinton Physical Therapy Center in Tennessee, agrees that strengthening is key to avoiding any injury. She notes that “it is important to strengthen the entire lower extremity, because the muscles that surround the hip are also the stabilizing muscles for the knees.” She suggests step-ups, squats and lunges, and using machines to do leg presses and hamstring extensions. Joyce reminds athletes to pay attention to their form during these exercises; never allow your knee to go past your toes. Robyn also points out that ankles need to have good mobility and strength as well; weak ankles can lead to poor landing positions and related injuries.

There are a variety of exercise programs for ACL injury prevention, including the PEP Training Program from ACL Project Prevent, and the 11+ complete warm-up developed by FIFA for professional female soccer players in Europe, which focuses on strength, plyometrics and balance. Lee emphasizes proper landing and deceleration (i.e., how to slow down) technique, increasing hip and knee flexion, and strengthening the hamstrings, glutes and hips, while Robyn suggests doing the following exercises first on a stable floor and then graduating to more unstable surfaces:

  • Single leg squats (without turning the knee inward)
  • Sideways walking with tubing or elastic bands (such as Stretchwell Fit-Lastic), creating tension to work the outside hip muscles
  • Single leg bridging, engaging the core and glute over the hamstring
  • Jumping, first on both legs and then on one leg, increasing the difficulty of the jumps

The position of no return. Click to enlarge.Robyn also warns against the position of no return, whether while doing exercises or, particularly, during activity. She says, “The position of no return is a very high risk position for ACL injury. Here the athlete is forward-flexed at the hip, the femur [upper leg bone] is internally rotated and adducted, the knee is in hyperextension and externally rotated, and the weight of the foot is focused on the ball of the foot.” Moving from this position greatly increases the chances of ACL injuries.

Stefania Della Pia, Program Director of Education for STOTT PILATES®, a Physiquality partner, also reminds athletes that Pilates is a great way to cross-train and strengthen outside their sport. She says lots of Pilates mat exercises strengthen the lower body, suggesting hip releases, heel slides or shoulder bridges with a ball underneath one foot, or doing balance exercises while standing on a BOSU. At a Pilates studio, athletes can work with an instructor on such apparatus as the reformer and stability chair, which both strengthen while reducing impact.

For help understanding and preventing ACL injury, consult with a Physiquality network physical therapist in your neighborhood. Locate the therapists nearest you with our online Find a Therapist search.



Lee Couret, PT, MS, is a physical therapist and owner of Southshore Physical Therapy, a Physiquality network physical therapy clinic in Metairie, Louisiana. Lee is a certified USA Cycling Coach and an active triathlete who has also completed the Ironman Triathlon.

Joyce Klee, PT, is a physical therapist and a co-owner of Clinton Physical Therapy Center, a Physiquality network physical therapy clinic, in Clinton, Tennessee.

Robyn Smith, PT, MS, SCS, is a physical therapist at The Center for Physical Rehabilitation, a Physiquality network physical therapy clinic with four locations throughout Grand Rapids, Michigan. Robyn lectures internationally on injury prevention and ACL injuries in the female athlete, and she co-authored a chapter on “Considerations for the Physically Active Female” in the book Musculoskeletal Interventions: Techniques for Therapeutic Exercise.

Susan Sigward, PT, Ph.D., ATC, is a physical therapist and Assistant Professor of Clinical Physical Therapy at the University of Southern California. Susan is the co-coordinator of ACL Project Prevent, a research project at USC that partnered with the University of North Carolina at Chapel Hill, the Santa Monica Orthopaedic Group, and CATZ Physical Therapy Institute (a Physiquality partner program) to investigate the biomechanics of female athletes and their predisposition to ACL injuries.

Stefania Della Pia is the Program Director of Education, as well as a Master Instructor Trainer, for STOTT PILATES®, one of Physiquality’s partner programs. Della Pia is certified as an ACE personal trainer and a Can-Fit Pro personal trainer specialist.



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For further reading, look through our selection of articles on youth ACL injuries, in addition to the below links:

ACL injury prevention. APTA, May 31, 2011.

Callahan, Christy. How to prevent knee pain while cutting in soccer. Livestrong.com, December 31, 2010.

STOTT PILATES. Athletic conditioning on the reformer. YouTube.com, December 16, 2010.

STOTT PILATES. Athletic conditioning on the stability chair. YouTube.com, December 16, 2010.

Stein, Jeannine. ACL injuries could be influenced by gender and which leg dominates, study finds. Los Angeles Times, August 2, 2010.

Back to basics: Squats. FitSugar.com, June 25, 2010.

Barone, Danielle. Injury primer: Treat knee injuries before they occur with knee injury prevention programs. ADVANCE for Physical Therapists & PT Assistants, March 8, 2010.

Brophy, Robert H., Holly Jacinda Silvers and Bert R. Mandelbaum. Anterior cruciate ligament injuries: Etiology and prevention. Sports Medicine and Arthroscopy Review, March 2010.

Stein, Jeannine. Preventing soccer-related knee injuries may be a training program away. Los Angeles Times, January 16, 2010.

The 11+ complete warm-up. FIFA Medical Assessment and Research Centre.

Soligard, Torbjørn, Grethe Myklebust, Kathrin Steffen et al. Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomized controlled trial. BMJ (British Medical Journal), December 9, 2008.

PTs: Appropriate exercise can help prevent ACL injuries in females. APTA, September 25, 2008.

Gilchrist, Julie, Bert R. Mandelbaum, Heidi Melancon et al. A randomized controlled trial to prevent noncontact anterior cruciate ligament injury in female collegiate soccer players. American Journal of Sports Medicine, August 2008.

Silvers, Holly Jacinda and Bert R. Mandelbaum. Prevention of anterior cruciate ligament injury in the female athlete. British Journal of Sports Medicine, August 2007.

PEP Training Program. ACL Project Prevent, University of Southern California Musculoskeletal Biomechanics Research Laboratory.

Silvers, Holly Jacinda, Eric Giza and Bert R. Mandelbaum. Anterior cruciate ligament tear prevention in the female athlete. Current Sports Medicine Report, December 2005.



The material and information contained on this Web site is for information only and is not intended to serve as medical advice or consultation.

Consult your personal physician before beginning any exercise program or self-treatment.