What is the ACL?
The ACL – anterior cruciate ligament – is probably the most important ligament in the knee. (A ligament connects one bone to another.) The ACL, which is located in the center of the knee, connects the thigh bone (femur) to the shin bone (tibia). The main function of the ACL is to stop forward movement of the shin bone on the thigh bone.
What causes ACL injuries?
Most ACL tears are non-contact injuries. You can tear your ACL when you twist your knee too forcefully, or when you plant your foot and then suddenly change direction.
What athletes are at an increased risk of ACL injuries?
ACL injuries seem to be increasingly common. In college football, the risk of tearing the ACL and needing to undergo reconstruction in a four-year career may be as high as 16 percent. High-risk sports are football, basketball, soccer and volleyball. Females are four times more likely to have an ACL tear than males are.
What does an ACL tear feel like? What are the symptoms?
Typically, the athlete will feel or hear a "pop" or a sense that the knee "gave out." The athlete is unable to continue due to pain and instability. The knee usually becomes swollen anywhere from two to six hours after the injury, and it will stay swollen for two to four weeks. When the swelling subsides, the instability is still present and will give the athlete a feeling of unsteadiness.
How is an ACL injury treated?
After a physical exam, an X-ray will be taken to rule out any fracture. An MRI (magnetic resonance imaging) scan will be taken to get a clear picture of the knee. The MRI will show the soft tissue (ligaments, cartilage and muscle) of the knee. The torn ACL will show up clearly on an MRI. If the athlete wants to continue in his/her sport, ACL reconstruction is necessary. Fifteen or 20 years ago, tearing the ACL meant an athlete’s career was over, but now it is just put on hold until ACL reconstruction surgery and rehabilitation have been completed.
What happens after ACL reconstruction?
The first week after surgery, the athlete will perform gentle range-of-motion exercises, isometrics for strength, and some weight-bearing exercise. As the time progresses, formal physical therapy is started, including advanced strengthening and balance activities.
After about eight to 12 weeks, sport-specific activities are added to the rehab program, such as hopping, jumping and agility drills. The athlete should be able to return to normal activity anywhere from six to nine months following the ACL reconstruction.
Are ACL injuries preventable?
No. ACL injuries are going to occur. However, training techniques have attempted to minimize the risk of tearing the ACL. These include fine motor control of the lower extremities as well as increasing strength, endurance and flexibility. Luckily, with advances in surgical techniques (like ACL reconstruction) and rehabilitation, an ACL knee injury is a season-ending injury – but NOT a career-ending one.
Injury prevention program may lower ACL injury risk in female athletes
Female athletes are two to eight times more likely to sustain ACL injuries than men competing in the same sport. Research shows that females tend to change direction ("cut," "jump" and "jump stop") differently than males, and it is those types of maneuvers that are often implicated in the dreaded "noncontact ACL tear," says Susan Joy, M.D., director of Women's Sports Health at Cleveland Clinic.
Studies of female athletes at the high school and collegiate levels have demonstrated that supervised training programs designed to improve leg strength and jump-landing technique may decrease ACL injury rates in volleyball and basketball players, Dr. Joy says. Emerging data suggest similar improvements in soccer players as well. Programs to improve lower body and trunk strength that subsequently retrain jumping and cutting mechanics seem to decrease the risk of ACL tear in girls and young women who participate in the strength and prevention program compared to those who don't.
To that end, Cleveland Clinic Sports Health now offers a jump training program – Jump-Right – that is designed to retrain how female athletes jump and land, to improve jumping and landing mechanics and increase leg strength, which may decrease the risk of serious knee injuries.
The six- to eight-week program is aimed at teaching female athletes proper jumping and landing mechanics, beginning with fundamental warm-up and jumping techniques, and gradually progressing to advanced-level plyometrics.
In addition to injury-risk reduction, our Jump-Right program may enhance athletic performance. Plyometric programs have been shown to increase vertical jump, improve acceleration and improve the ability to change direction. All of these factors are instrumental to an athlete's success.
For more information on the Jump-Right Training strength and injury prevention program, call 216/444-6000.
Training programs designed to teach, strengthen and condition women to land properly may significantly decrease the risk of ACL injury. Illustrations show proper landing technique vs. improper landing.