By Andy Boone and Julie Shepherd
We’d like to kick-start a discussion around the rising number of Anterior Cruciate Ligament (“ACL”) injuries among our female student athletes. Equip Sports Performance is aware of at least 12 Marin County female student athletes who suffered ACL injuries in the last three years alone. Although we cannot prevent all ACL injuries, it’s been shown that there are in fact steps we can take to reduce the rate of occurrence. So, what do we know, and what steps can we take to address this problem?
This is by no means intended to be a scholarly paper, but rather anecdotal and again, our effort to begin a conversation. Why do so many ACL injuries occur? Are females at greater risk than males? What steps can individual athletes take to help mitigate risks? Are there training principles and activities whole teams should implement and prioritize?
For starters, let’s first make sure we are all on the same page. What is the ACL and what are the most common injuries?
The ACL is one of the key ligaments which helps stabilize the knee joint. The ACL performs this function by attaching to the femur on one end, and to the tibia on the other. It is the primary restraint to forward motion of the shin bone or tibia. The ACL prevents the tibia from sliding too far forward and also helps stabilize other movements at the joint, including angulation and rotation.
Student athletes typically sustain ACL injuries one of two ways. The first is through contact. An athlete may run into another athlete resulting in player to player contact or on more rare occasions, he/she may run into a stationary object ike a goal post. Rare indeed, but it does happen.
The second and more common is the non-contact ACL injury. Non-contact ACL injuries typically occur when athletes cut, change direction, jump, land and/or abruptly decelerate. We believe the most common event causing ACL injuries is landing and/or abrupt deceleration. It is estimated that this event causes about 70% of all ACL injuries.
It’s been shown that female athletes are approximately eight times more likely to injure their ACL when compared to same-age males. It’s also believed there are several reasons female athletes are more prone to this specific injury. First (and as strange as it may sound), female athletes may naturally over develop quadricep strength compared to hamstring strength. On its own and under normal demands this is neither unnatural nor problematic. However, under high demand activities involving high stress on the knee joint, balance between the quadricep and the hamstring becomes essential as both must contract working together to help stabilize the knee. This co-contraction is especially important during activity which include cutting, pivoting and changing directions. If the hamstring muscle is not strong enough to assist and/or absorb impact, it cannot stop the tibia (shinbone) from moving too far forward, which very simply overextends the ACL increasing the risk of a potential tear.
In addition to overdeveloped quadriceps combined with poor hamstring strength, it’s been shown that many female athletes are prone to landing with hips and knees extended or straight and often with their knees turned inward or what’s referred to as a valgus position. Landing in this position increases tension on the connective tissues of the knee and is linked to a higher risk of ACL injury.
With the above challenges in mind, supporting a large number of Marin County female student athletes across a variety of demanding athletic environments, Equip Sports Performance has set forth a basic program philosophy. Our training program aims to reduce the incidence of ACL injuries which occur during both training and competition.
Ideally, sports performance and training programs should focus on repeated activation and strengthening of the hamstring musculature and supporting soft tissues. Activating and strengthening the hamstring musculature should be prioritized, built into in-season and off-season training, daily warm-ups and never neglected on game day.
Training sessions with these principles may progress to weighted single leg deadlifts and weighted trap bar deadlifts. However, when athletes begin a strength program they should work with a coach who understands bodyweight movement progressions in advance of weighted options. For example, the deadlift begins with first learning how to brace and activate musculature to ensure spinal integrity. This happens unweighted while an athlete lies on his or her back or holds a static plank position. Once proper bracing is mastered, athletes learn to correctly hinge with the hip as a prerequisite to lifting weighted implements from the floor. Once an athlete learns to hinge correctly, he/she may begin lifting light kettlebells and one day they may progress to a trap bar or barbell lift, both more complex movements.
Sports performance and training programs must teach jumping and landing techniques including learning how to load the posterior chain properly in advance of box jumps and other multidirectional jumping activities.
At Equip Sports Performance, it is not uncommon to meet high-level athletes including collegiate, high school, club lacrosse, basketball and soccer players, who have never learned to jump and land correctly. We also observe coaches, parents, and other well intentioned adults incorporating advanced plyometric training principles (the box jump!) into training programs, however likely unaware of the above foundational movements, and inherent risks that may result from these training efforts.
Not unlike the above hamstring strength principles, training sessions aimed to teach jumping and landing may first begin with bracing and activating the correct musculature to ensure spinal integrity. Following this, hip hinging is learned. Once mastered, athletes may then progress to low box jumps, jumping and landing in place, and broad jumps. Advanced plyometric training may include hurdle jumps, and single leg bounding, but only after beginning jumping and landing techniques have been mastered.
ACL injuries are an unfortunate part of sport. These injuries will occur during both training and competition. However, if there are in fact steps we can take collectively to help reduce the risk of these injuries, isn’t it time we consider how clubs, coaches, and our student athletes spend time training?
A reduction in time spent teaching and learning the technical side of a given sport may increase time spent building sound movement progressions aimed specifically at reducing occurrence of injuries. By including thoughtful, intentional, and progressive strength training along with progressive jumping and landing techniques, we believe a student athlete reduces the risk of facing ACL woes. Perhaps more than an opportunity to train this philosophy, it may be our collective responsibility.
We’d like to know what you think! To learn more about our program or if you’d like to share your thoughts please email Julie Shepherd at 415-686-1493 or firstname.lastname@example.org.