Anterior cruciate ligament (ACL) tears are common in female athletes, and they have serious consequences. Most of these injuries require surgery and 6 months to a year of rehabilitation. They also increase the risk of arthritis in the knee later in life. (Check out STACK's comprehensive guide on the ACL.)
Recent research suggests that certain types of training can reduce the risk for ACL injury. But to understand how injury prevention programs work, it is important to understand the mechanism of the injuries. In females, most ACL tears occur when landing from a jump—e.g., after a layup in basketball or a header in soccer—or when cutting too quickly when changing direction. As the athlete lands or plants on the leg, the knee either hyperextends or buckles inward to what researchers call "the point of no return." This is different from the experience of most male athletes, who more commonly tear the ligament when being tackled or hit in the knee.
ACL injury prevention programs try to correct the biomechanics that put females at risk for reaching that "point of no return." Such programs should contain the following four components:
Hamstring, hip abductor and gluteus maximus strengthening
These muscles balance the pull of quadriceps and hip adductors to reduce risk of strain on the knee. (Find out why strong hamstrings decrease ACL injury risk.) Examples:
- Hamstring strengthening: Physioball Hamstring Curls (3 sets of 10-15 reps) or Single-Leg RDL (2 sets of 15 reps)
- Hip abductor strengthening: "Inchworms" (perform to slight muscle fatigue), Hip Hiking (2 sets to slight muscle fatigue on each leg)
- Gluteus maximus strengthening: Single-Leg Squats (3 sets of 10, each leg), Bridge with Leg Raise (15-30 reps each leg)
Studies have shown that poor core strength and coordination can contribute to injury risk. Examples of core strengthening:
- Front Planks (3x30-60 seconds)
- Lateral Planks (3x10-30 seconds each side)
- Single-Leg Kneeling with Ball Tossing (15-30 reps each side)
- Kneeling Ball Roll-Outs (3 sets of 10-12)
- Single-Leg Lateral Wall Leans (2 sets of 15-20 reps each side)
Studies have shown that females jump and land differently from males. Training to jump and land without letting the knees go into a "valgus," or inwardly rotated position, can reduce risk of ACL injury. This training should start with basic two-leg jumps in place, then progress to forward/backwards jumping and lateral jumping. Perform 2-3 sets of 10 reps. Once form improves, then carefully progress to single leg jumping using the same progression—in place, forward/backward, and lateral hops. Stand in front of a mirror to check your form, and make sure your knee is not turning inward. Also, don't let the knees go past the toes when landing.
Balance training, or perturbation training, can help the knee stay in a more stable position during sports maneuvers—e.g., when battling an opponent for a soccer ball or boxing someone out under the basketball hoop. Examples of exercises include:
- BOSU Ball March and Hold (20-30 reps each leg)
- Single Leg Balance with Forward/Back/Lateral Band Kicks (2 sets of 10-15 each leg)
- BOSU Squat and Hold with Partner Perturbation (3 sets of 30-45 seconds)
To find an ACL injury prevention program near you, contact your local hospital sports medicine program, such as Cleveland Clinic Sports Health, The Ohio State University Sports Medicine, or Cincinnati Children's Hospital. Other programs, such as the FIFA 11+ program, are available online. These programs should be supervised by a trained professional to make sure that all sessions are completed with proper form.