Preventing ACL injuries in athletes

A common knee injury that occurs in athletics is a torn anterior cruciate ligament. The ACL is one of the major ligaments that help stabilize the knee joint.

The majority of ACL injuries occur when an athlete misses a landing from a jump, pivots quickly while changing direction, or decelerates abruptly. To help prevent ACL injuries in athletics, special ACL prevention programs have been developed. These prevention programs are becoming more popular in youth sports and generally include exercises to help strengthen muscles and emphasize balance, power, flexibility and agility.

Plyometric exercises and balance drills help improve neuromuscular conditioning and reaction time and help decrease the risk of ACL injury.

ACL prevention programs also focus on proper leg position when cutting or landing jumps and avoidance of at risk situations. Many athletic organizations are now using an ACL conditioning program as a basic part of sports practice.

One such program is the Prevent Injury and Enhance Performance program. The PEP program was developed by the Santa Monica Orthopedic and Sports Medicine Group.

There are generally five components to this program: Warm-up, stretching, strengthening, plyometrics and agility drills to address potential deficits in the strength and coordination of the stabilizing muscles around the knee joint.

Emphasis is placed on straight up and down jumps without excessive side-to-side movement, and soft landings. Specific instructions for the PEP Program can be found online at www.aclprevent.com.

Here are some examples of the activities involved in the PEP program.

Warm-up

Warming up your muscles helps to reduce the risk of injury.

A. Jog line to line or cone to cone.

Complete a slow jog from near to far sideline. Use good running technique. Keep the hip/knee/ankle in straight alignment without caving in or the feet whipping out to the side.

B. Backward Running.

Run backward from sideline to sideline. Land on your toes without extending the knee. Stay on your toes and keep the knees slightly bent at all times.

Stretching

Stretching helps to improve flexibility, overall mobility, and reduce your risk of injury. Incorporate a short warm-up before stretching. Never stretch a "cold muscle."

A. Quadriceps Stretch.

Stretches the front thigh muscle. Place your left hand on our partner's left shoulder. Reach back with your right hand and grab the front of your right ankle. Bring your heel to buttock. Keep knee pointed down toward ground. Hold for 30 seconds and switch sides.

B. Hamstring Stretch.

Stretches the hamstring muscle on the back of the thigh. Sit on the ground with your right leg extended out in front of you. Bend your left knee and rest the bottom of your foot on your right inner thigh. With straight back, try to bring your chest toward your knee. Do not bounce. Hold for 30 seconds; repeat with the other leg.

Strengthening

Increasing leg strength can help stabilize the knee joint.

A. Walking Lunges (1 minute).

Strengthens the thigh muscle. Lunge forward leading with your right leg. Push off with your right leg and lunge forward with your left leg. Drop the back knee straight down. Make sure that you keep your front knee over your ankle. Control the motion and try to avoid your front knee from caving inward.

Plyometrics

Plyometrics are explosive exercises to help build power, strength, and speed. Helps to teach athletes to land softly from a jump with a bent knee and bent hip.

A. Lateral Hops over a 2-inch cone (30 seconds).

Helps increase power/strength emphasizing neuromuscular control. Stand with a 2-inch cone to your left. Hop to the left over the cone, softly landing on the balls of your feet and bending at the knee. Repeat hopping to the right.

B. Forward/Backward Hops over 2-inch cone (30 seconds).

Similar to lateral hops, but hop forward and then backward over the cone. Land on balls of your feet and bending at the knee. Maintain a slight knee bend.

Agilities

A. Forward Run with 3-Step Deceleration.

Teaches the athlete how to properly accelerate and decelerate while moving forward.

Starting at the first cone, sprint forward to the second cone. As you approach the cone, use a 3-step quick stop to decelerate. Continue on to cone 2 using the same strategy to deceleration. Do not let your knee extend over your toe. Do not let your knee cave inward.

B. Bounding Run (44 yards).

Helps increase hip flexion strength/increase power/speed. Starting on the near sideline, run to the far side with knees up toward chest. Bring your knees up high. Land on the ball of your foot with a slight bend at the knee and straight hip. Increase distance as this exercise gets easier.

If you have questions about athletic sports injuries, call Rehabilitation Services of the Blue Mountain Health System at 610-377-1300.

Gary Higgins is a physical therapist and the director of Rehabilitation Services at Blue Mountain Health System.