SAN DIEGO, Calif. (Sept. 29, 2003) – According to the American Academy of Orthopedic Surgeons, nearly 6 million people visit orthopedic surgeons each year because of knee problems. The American Council on Exercise (ACE), America’s nonprofit fitness advocate, offers advice regarding proper biomechanics and a sound exercise training program that may reduce an individuals’ risk for sustaining a sports-related knee injury.
Injuries to the ACL are among the most common of all sports-related knee injuries. Each year in the United States, approximately 250,000 people tear or rupture the ACL. An ACL becomes torn when it is stretched beyond its normal range of elasticity. The ACL stabilizes the knee and prevents the tibia from sliding forward beneath the femur. Once the ligament tears, it does not heal; it remains loose. Injury to the ACL usually requires surgery.
“Movements where there is a sudden deceleration, or a hard twist or change in direction, all put stress on the ACL,” said Dr. Cedric Bryant, PhD., chief exercise physiologist for ACE. “It’s also common for athletes to injure themselves where there is a hard planting of the foot, or landing with the knee extended instead of flexed.”
The body is a link system, in which every muscle in the body controls the ACL and the knee. Rather than concentrating on knee exercises, athletes should strengthen the body’s core muscles (hips, feet, truck, and shoulders) to reduce the risk of a knee injury. Exercises should include movement on all three planes: front and back, side to side, and rotational.
The following exercises are designed to imitate-in a controlled manner-the movements that can be found in different sports. These exercises are examples of chain-reaction movements from the video, Lower Extremity Performance and Prevention by Gary Gray, P.T. founder of Functional Design Systems in Adrian, Mich.
- 3-D Matrix Hop- This is a functional exercise that simulates the same reaction that you would experience as you ran forward, cut to the right, ran forward again and then cut to the left. You rotate off the right leg, propel back and then off the left leg, and back.
- 3D Matrix Lunge- This lunge calls for a standard forward lunge, the a diagonal or 45-degree lunge to each side, as well as a lateral lunge to the right and to the left.
- Single-Leg Balance Squats- These squats call for driving the legs forward, then putting one leg in front of the other leg behind to create a chain reaction. Next, you can progress by driving one leg to the side to engage the hip, trunk and lower extremities.
- Mirror Matrix- The 3D Matrix Lunge can be made more reactive by doing this exercise. Partners take turns anticipating and following each other as they move through the matrix pattern. Add arm movements to increase the intensity and complexity of this activity.
- One-Legged Hopping- This exercise starts on either your left or right foot jumping over an imaginary straight line. These hops have a dramatic influence on the entire chain reaction, how the shoulder, the trunk and especially the abdominals control what happens at the pelvis, the knees and the feet.
- Two-Legged Jumping- Stay forward on the balls of your feet and jump with both feet right to left over an imaginary straight line. From there you can incorporate a rotational jump as well.
A complete article on ACL injuries and photographs of the top six exercises can be found in the August/September 2003 issue of ACE’s Certified News.
The American Council on Exercise (ACE), America’s Authority on Fitness, is a non-profit organization dedicated to promoting the benefits of physical activity and protecting consumers against unsafe and ineffective fitness products and instruction. As the nation’s “workout watchdog,” ACE sponsors university-based exercise science research and testing that targets fitness products and trends. ACE sets standards for fitness professionals and is the world’s largest nonprofit fitness certifying organization. For more information on ACE and its programs, call (800) 825-3636 or log onto the ACE Web site at www.acefitness.org.