HOW TRAINING CAN HELP PREVENT ACL INJURY
by Rick Meldrum
Injuries to anterior cruciate ligament (ACL) is one of the most studied injuries to date. An ACL injury happens when the shin is stationary while the upper leg is either hit or twists in an opposite direction of the shin. Roughly 200,000 ACL injuries occur annually in the US alone. The majority of those injuries happen to athletes ranging in ages from 15 to 45 years old. Roughly half of those injuries need ACL reconstruction surgery. Around 70% of those ACL injuries are during non-contact situations, meaning that the athlete suffered the injury on their own accord during play.
In non-contact situations, this injury occurs when the athlete is attempting to decelerate, change direction too quickly , or stop suddenly. Contact ACL injuries usually occur in tackling sports such as Rugby or Football. They are the result of a direct lateral blow to the knee, often times effecting other ligaments as well as the ACL. Female athletes are at a greater risk to sustaining an ACL injury. This increased risk for female athletes is a combination of anatomical factors, but the largest contributor is neuromuscular control and abilities. Since this is such a prevalent injury, there is a large effort in the sports performance industry to combat ACL injuries through preventative measures. Early exposure to neuromuscular training and resistance training can help limit the likelihood of ACL injury.
One of the ways we help athletes here prepare is by conducting a Functional Movement Screen, along with some performance tests . The FMS is consists of 7 different movements, designed to identify any asymmetrical movement patterns. The movements are graded either a 1, 2, or 3, with 3 being the best score. 5 out of the 7 movements are scored for right and left sides, with the lower of the two scores tallied towards the total. It is generally agreed upon that a score of 14 or less is indicative of high risk towards injury. The FMS is an attempt to see if the athlete in question has enough body control, and to see if their show an inward knee motion during landing mechanics. This leads us to developing the proper training program for our athletes. For ACL injuries, neuromuscular training focuses on training the athlete in proper knee mechanics. This involves training the athlete to land and absorb ground forces, as well as their own body’s forces.
The specifics of neuromuscular training may differ from one person to the next, but the general qualities developed are balance and control, muscular strength, and flexibility. Plyometrics, with an emphasis on proper landing mechanics, is a major factor in reducing the risk of an ACL injury. Dynamic Knee Valgus is the termed used to describe the athlete’s knee collapsing medially upon landing or planting. This happens because of overactive hip and leg adductors & internal rotators, in combination with weak abductors and external rotators. To correct this, we target the adductors with self-myofascial release techniques and stretching. We also look to strengthen the gluteal muscles, as they play an integral role in balance. Developing strength in both the quadriceps and hamstrings is also important. By increasing the strength of the muscle groups acting on the knee, we can reduce the risk of ACL injuries by being able to better handle the large forces involved with activity.
Practical strength training for performance and injury prevention includes plyometrics, with a focus on landing mechanics . We also increase the athlete’s proprioception and balance by performing unilateral exercises, i.e. split squats and single leg RDLs . These types of exercises are like 2 for 1s. Not only do we increase the athlete’s proprioception, but also increase strength in the same movement patterns that are happening on the field .
An example of a training program for collegiate women’s soccer players is as follows:
1A) Vertical Depth Drop 3 sets of 4 reps
1B) Banded Side Step 3 sets of 8 reps each side
1C) Single Leg Mini Hurdle Jump 3 sets of 2 reps each leg
2A) Barbell squat 3 sets of 5 reps at 75% 1RM
2B) Lateral Plank Hold 3 sets of 30 seconds each side
2C) Partner assisted Glute-Ham Raises 3 sets of 6 reps with 3 to 5 second eccentric movement
3A) Rear foot elevated Split Squat 3 sets of 8 to 12 reps
3B) Bodyweight plank holds 3 sets of 45 seconds
3C) Single Leg Romanian Deadlifts 3 sets of 6 reps each leg
The above would be 1 of 2 or 3 workouts conducted by the athlete in a single week, usually with a day of rest between each session.
Old wisdom for serious limb injuries used to be immobilize and let the body heal. Now there is a much more active approach to immediate care and rehabilitation with ACL injuries . Moving the injured limb and reducing swelling are among the top goals in rehabilitation for ACL reconstruction surgery. Because of the damage an ACL injury sustained by the athlete can be, there is a premium placed on strength coaches and athletic trainers who have experience creating effective plans for combating the risk of ACL injury. Understanding the mechanisms, and possible causes of ACL injury, in conjunction with risk assessment protocols, can have a significant effect in reducing the risk of ACL injury in those athletes susceptible to ACL injury .
Rick Meldrum is a certified strength and conditioning specialist (CSCS), and a club coach for USAW. He is also certified by the Collegiate Strength & Conditioning Assoc. as well as Functional Movement Systems. He is the Head Strength and Conditioning Coach at Zelos Athletics in Westborough, MA.