It is estimated that over 350,000 ACL injuries occur each year in youth sports. With athletes starting at a younger age, competition seasons getting longer and more intense, the number is projected to be higher in the coming years. It is important for young athletes to participate in structured strength training programs to learn proper body control and drastically reduce the likelihood of these injuries.
What exactly is an ACL injury?
The anterior cruciate ligament (ACL) connects your femur to your tibia, providing essential stability to the knee joint. Essentially, the ACL prevents the tibia from sliding forward relative to the femur during movement and resisting potentially harmful rotational movements of the knee.
What causes an ACL injury?
While ACL injuries can occur in response to a contact injury, they are mostly caused by a non-contact movement. They occur during the landing phase of a jump, rapid change of direction, and single leg bounding activities. During these sports-related movements, the knee is under a high amount of load.
Ideally, the muscles that act on both the hip and knee would help absorb this load, reduce any undesirable movement at the knee, and keep the lower limb in optimal alignment. But unfortunately, this is often much easier said than done.
If an athlete doesn’t have proper control of their body or proper landing technique, they are at a much higher risk for ACL injuries. In fact, females are 4-6 times more likely to suffer an ACL injury because of the Q angle. The Q angle is the angle formed by a line drawn from the anterior portion of the pelvis to the center of the knee, and then a line from the center of the knee to the tibial tuberosity.
This increased angle is the result of females having wider hips than their male counterparts, which can increase the risk of the knee collapsing into a valgus position, and therefore resulting in an increased risk of ACL rupture.
Valgus knees are one of the biggest precursors to ACL injuries because it is a lack of glute activation and ability to absorb force. Below are three of the best exercises to incorporate into your training program to prevent valgus knees and activate your glutes!
- Monster walks – these are a great exercise to strengthen the median glutes while reinforcing proper knee alignment.
Performing the drill:
Place a mini band below the right below both knees
Get into an athletic position with your feet a little bit wider than shoulder width.
Drive the knees out as if you’re trying to snap the band, keep the knees driving out during the entire duration of the drill.
Slowly walk forward, staying low and maintaining equal distribution across the whole foot.
If the drill is too easy, add an additional band across the ankles.
Make sure the athlete stays in an athletic position during their steps, keeping the hips back and driving the knees out.
- Depth Drops – this exercise is a great way to teach the athlete how to land properly. Being able to absorb force from an elevated position directly relates to almost every sport. When you come down from a rebound in basketball, or catch a high ball in baseball, learning to land properly will not only help prevent injuries but set your body up to perform another athletic move right after. i.e. landing into a sprint or landing into a throw.
Performing the drill:
Use an elevated surface, a 12 – 16 in plyobox will work. (more advanced athletes can use a 24 in plyobox)
Step off the edge of the box as if you’re walking the plank
Land in an athletic position with your hips back, chest up, knees out, and weight evenly distributed across your feet.
Make sure the athlete is landing as soft as possible, being able to absorb the impact will strengthen the hamstrings and take the pressure off of the knees.
Try and land in an athletic position opposed to landing and then sinking into one.
- 3-way stabilization – this is a staple injury prevention exercise at Maximize Potential. The drill forces the athlete to focus on stability through different ranges of motion and continuous changes in the center of gravity. Being able to activate the glutes and stabilize the knee in a fixed position will translate over to the field of play.
Performing the drill:
Set out three cones around your starting foot – one in front, one to the outside, one in the back. This will be your targets for your elevated leg.
In your bare feet, stand on one foot. Make sure the athlete is standing in an athletic position (knee bent, hips back, chest up, knees out). Move the elevated leg towards the front cone then back to the center, perform this movement for each cone in sequence.
If the drill is too easy, add an unstable surface underneath the planted foot to develop more strength and activation.
Perform this drill in slow controlled reps, this drill is designed to produce stability.
Make sure the athlete stays in an athletic position during the entire drill, doing their best to not reset the elevated foot.
Athlete ACL Injury Prevention Protocol:
3-way stabilization: 2 sets of 10 each way, each leg
Monster walks: 3 sets of 10 steps forward and backward (20 total steps)
Depth Drops: 3 sets of 5 drops
Kobayashi, Hirokazu, et al. “Mechanisms of the anterior cruciate ligament injury in sports activities: a twenty-year clinical research of 1,700 athletes.” Journal of sports science & medicine 9.4 (2010): 669.
Hewett, Timothy E., et al. “Mechanisms, prediction, and prevention of ACL injuries: cut risk with three sharpened and validated tools.” Journal of Orthopaedic Research 34.11 (2016): 1843-1855.
Hewett, Timothy E., et al. “Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: a prospective study.” The American journal of sports medicine 33.4 (2005): 492-501.
Kızılgöz, Volkan, et al. “Analysis of the risk factors for anterior cruciate ligament injury: an investigation of structural tendencies.” Clinical imaging 50 (2018): 20-30.
Ishida, Tomoya, et al. “The effects of a subsequent jump on the knee abduction angle during the early landing phase.” BMC musculoskeletal disorders 19.1 (2018): 379.
Cavanaugh, John T., and Matthew Powers. “ACL Rehabilitation Progression: Where Are We Now?.” Current reviews in musculoskeletal medicine 10.3 (2017): 289-296.
Nessler, Trent, Linda Denney, and Justin Sampley. “ACL injury prevention: what does research tell us?.” Current reviews in musculoskeletal medicine 10.3 (2017): 281-288.