In the eyes of an athlete, ACL tears are arguably one of the most devastating injuries that an athlete can face, often removing them from their sport for a season, if not longer. They are now being viewed as an epidemic in youth athletes and beyond, and Chris Gobrecht, the head women’s basketball coach at Yale University, can attest to that as he “can tell you firsthand that ACL injuries wreak havoc on seasons, self-esteem, athletic careers and physical health” (Marx). While there are many different prevention methods that studies have claimed help save these athletes, some of the healthiest, most active young individuals just cannot seem to escape the injury due to certain biodynamic factors that occur in popular sports such as soccer, basketball and volleyball. While this injury is seen in both males and females, females are now suggested to be more prone to the injury. Females are at greater risk to tear their ACLs in athletics than males due to biomechanical differences that are seen in the female body that affect performances. These differences can cause women to take very distinct steps in order to care for and prevent these injuries from repeating themselves. 

The anterior cruciate ligament (ACL) lies on the front-facing part of the knee, directly under the patella, working in conjunction with three other primary ligaments to connect the bones that help stabilize the knee. Movements, such as rapidly changing direction, sudden stopping or slowing down, landing or jumping while twisting or a sudden blow to the kneecap, all contribute to sprains, or complete or partial tears. Signs include swelling of the knee, and often times the athlete will feel a pop and their knee will completely give out, causing them to hit the ground. (Orthoinfo). Walking will often be difficult or near impossible without assistance, and tenderness along the joint-line is observed. While physically males and females have the same structural makeup, their susceptibility comes down to the way that they move and prior training that make certain reflexes and move differently, putting pressure upon the ACL (Orthoinfo). 

ACL injuries occur with a “four to six-fold greater incidence in females compared to male athletes playing the same high-risk sports” (Osborne). One of the multiple reasons this occurs is due to the genetic muscular makeup of the hamstring and the quadriceps, giving them a strength imbalance that causes instability to the knee. Females tend to lean slightly forward, putting pressure on their quadriceps rather than hamstrings, which can cause them to twist and fall when switching their weight, or easily lose their balance upon sudden impact. In comparison to females, male athletes tend to “decelerate using their hamstring to absorb the change in speed,” stabilizing their knee more efficiently, reducing their risk of injury more than females (Osborne). 

While observing an athlete in motion, the biodynamics between the male and female bodies differ significantly upon certain movements that are seen in high-impact sports, such as soccer. When women jump, their landing positon makes them vulnerable to injury as they often “land with their knee in a straight position, transferring the force of impact to the knee joint,” causing their ACL to tear (Cluett). Landing in a flat-footed position rather than on the balls of their feet also puts women at a disadvantage. Because of this position, a force is not exerted onto the calves and the knee is not in proper position, causing it to buckle in and tear the ligament. Males on the other hand “tend to absorb more of the energy of impact by landing with their knees bent,” allowing for more control and stability, limiting their susceptibility to injury in comparison to females (Cluett).

Women also tend to have a wider pelvis, which is an anatomical disadvantage when it comes to sports and sustaining injuries. This factor “makes the thigh bones angle downward more sharply than in men,” and as a result makes for a greater “Q-angle,” which is the angle between the quadriceps muscles and the patella tendon (Horwitz). The disadvantage of this factor is that a larger Q-angle leads to a greater amount of pressure on the inside of the knee, which is what leads to ACL tears. The ligaments located inside of the knee also tend to have greater laxity in comparison to males, who have muscles dominance over ligament dominance, giving them more control. Females’ individual muscle tissue has a greater elasticity in comparison to males and “excessive joint motion combined with increased flexibility may be a significant contributing factor in the higher rate of torn ACLs among women” (Horwitz). 

Another contributing factor is the way that females’ lower extremity is aligned, placing vulnerability upon the kneecaps. Women tend to have what can be seen as a “knock-knee” alignment, where their kneecaps “angle in and touch one another when the legs are straightened.” (Cluett). Movements of the lower extremity, such as running, twisting, kicking and jumping all place a greater amount of stress on the knee ligaments due to malalignment, making the easily stretched or torn, leading to a surplus of injuries seen within evolving female sports. While these are common causes, there are multiple precautions that can be taken to decrease ones chances of further injury.

A proper warm-up can be viewed as being one of the simplest ways to ensure safety amongst exercise or physical activity, but often times it is one of the most overlooked concepts, resulting in damage that could potentially hurt an athletes career. The benefits of increased blood flow to working muscles, which in many cases is the knee, “results in decreased muscle stiffness, reduced risk of injury and often, improved performance” (Quinn). Body temperature is also increased, which improves muscle elasticity, reducing the risk of strains and pulls and an increased range of motion. In many sports, such as soccer and basketball, these factors directly benefit the motions that put females in risk, such as jumping, twisting, pivoting and landing, due to an increase in flexibility and greater range of motion, preventing injuries such as ACL tears to occur. 

Doctors, such as Maria Osborne of the University of Colorado Health, are also claiming that women are more vulnerable to ACL tears due to their differences in circulating hormones throughout the body such as estrogen, which promotes the development of the female anatomy, as well as relaxin, a hormone that alters the body in preparation for labor. These hormones both directly affect the ligaments “strength and flexibility and the fluctuations of the hormone may influence the function of the nerves and muscles” (Osborne). 

15-year-old Michelle Backus of Gailthersburg, Maryland is one of the thousands of examples of a young athlete who is specializing in a certain sport, her sport being soccer, and falls short due to sustaining this injury. Her injury occurred while she was “maneuvering a teammate during soccer practice when she heard ‘a pop’ coming from her left knee” (Medline), causing instantaneous pain. Backus was aware of what had happened after hitting the ground immediately, describing the pain to be equivalent to “glass breaking” (Medline). Her injury was caused by one of the many ways that increase females risk, which is a combination of sudden deceleration combined by landing in a “knock-knee” position, creating immense vulnerability to the athlete. Backus followed the common steps that most athletes take to get back into the game as soon as possible, which is a diagnosis and an initial round of physical therapy to test her range of motion prior to surgery. After the surgery, Backus began six months of physical therapy, where she practiced how to jump and land properly to minimize her chance of reinjuring herself again.

Often times, the steps that athletes go through in the rehabilitation process “which includes balance, and strengthening exercises performed more than once a week,” prior to injuring themselves, can not only save them from facing this injury and other again, but can be applied to other athletes to keep them from sustaining an ACL or meniscus tear in general (Spindler). The steps taken in proper training can keep them out of surgery and on the field. Despite their biological differences, women are still able to lower their risk substantially if they target their biomechanical disadvantages, such as the way they move and the angles their bodies are prone to move at when pivoting, running, jumping and landing. 

According to doctor Jonathan Cluett, a certified sports medicine physician, the top way that athletes can minimize their susceptibility in high-impact sports is with the use of neuromuscular training programs that retrain one’s muscles and strengthen them through proper movement. This unconscious practice is the process in which the body is taught better “biomechanic movements and improved control of these dynamic stabilizers” (Cluett). This process specifically targets “deficits in dynamic stabilization of the knee” providing increased neuromuscular control (Cluett). These programs primarily involve stretching, plyometrics, which is where muscles exert maximum force in a short period of time, such as box-jumps, and overall strength training. This form of training, which can be viewed as “PEP”, Prevent injury, Enhance Performance, teach the athlete how to pivot properly and move and jump from side-to-side all without exerting maximum force on the ACL. While this tactic is often done after an athlete has torn their ACL and is training to get back in the game, doing it as part of a standard training method increases the game while decreasing the susceptibility of all athletes, especially females. 

Dr. Schwartzberg of Orlando Orthopedics offers a similar strategy, but places a different focus on preventing ACL tears in female athletes, which will also be beneficial in the overall process of limiting the amount of injuries seen amongst the female population. Schwartzberg emphasizes how “it is important to train the body year-round, not just during specific sports seasons,” which will limit atrophy, which is the weakening of muscles due to inactivity. This principle tied in with neuromuscular training could immensely decrease the number of injuries seen per year (Schwartzberg). While athletes are not playing their sport, off season training in an elite setting is crucial so that players re-enter the game at the same, or advanced, level compared to when they last played. Prevention awareness and education is another theory that Schwartzberg believes is crucial and is the first step to working against these devastating injuries. Before physically doing the steps, players must learn why they are doing them and the benefit that they have in the long run towards their athletic careers. 

Dr. Robert Marx focuses in on an intense study on the overall perception of the ACL and its injuries, and devotes an entire study within his book “The ACL Solution” to designing an effective prevention program, which focuses on females specifically in mind. Focusing in on the longevity of the ACL being a recognized, common injury in sports, Marx identifies that the “program finds its roots in the 1990s, in Norway” in the sport handball, where the mechanism of the injury was first discovered and the first rehabilitation programs began forming, guiding the ones in place today (Marx 70). Marx took concepts dating back to the 1990s, modernizing and simplifying them for common understanding and grouping them together in what can be viewed as “proprioceptive training”, which, in simpler terms means balance. This program would incorporate simple balancing acts which eventually evolve into athletic stances such as “planting, cutting, and landing from a jump” (Marx 16). 

Implementing this program starting with young athletes, the directions were kept simple to ensure that they understand what is going on. The Norwegian physicians developed a simple concept to be maintained while a young population and beyond, which is “knee over toe” that can easily be remembered by all athletes (Marx 121). This concept relates to the idea of valgus position and the danger that is causes in sports amongst a female population. If an athlete focuses on maintaining her knee in a position above her toe, rather than in a lateral bow-legged position, then the tibia has a decreased risk of sliding forward of the femur and tear the ACL. To incorporate the concept of balance in a prevention, the exercise plan Marx adopted that is recommended includes the use of wobble-board, the floor, and a balance mat to transition between the two. 

By combining these tactics and focusing on core stability, balance, and retraining the body for neuromuscular control, the risk of a female tearing her ACL is reduced, along with 

 “ankle and overuse injuries that keep athletes off the field just as often” (Marx 74). Dr. Jay Hertel announced at the 2010 American Orthopedic Society for Sports Medicine that after analyzing seven studies of ACL prevention programs between 1999 to 2008, he found that participation in this kind of program reduced the risk of noncontact ACL injury by a staggering 71%, showing how simple and crucial the prevention program can be (Marx 74). 

Despite many physicians agreeing that females are more susceptible to ACL tears in comparison to males, there are those physicians who will challenge it as well, such as Richard Nordenvall who partook in 22-year study from 1987 to 2009 in Sweden where ACL tear surgeries were linked to post-traumatic osteoarthritis. The age-range in this study consisted of ACL patients nationwide in Sweden ranging from 15-60, concluding that “men represented 63% and the mean age at time of diagnosis was 29 years,” differing from the idea that women are “four to six times more likely to tear their ACL than males” (Osborne). However, the scope gives way to a much larger population than strictly athletes, and does not focus strictly on the teenage population which is where the majority of athletic ACL injuries occur, therefore making it flawed while comparing it to the athletic statistics in the United States. While this study may be accurate, in an athletic population where the body is continuing to grow and develop, the rate of females tearing their ACL in a sporting event is significantly higher than those of males.

In today’s society, individuals of all ages are being pushed to maintain a healthy lifestyle starting from a young age, whether that includes eating right, taking the stairs, or picking up a sport; however, many are not aware of the proper way to do so in order to prevent an injury from occurring. In addition to just simply exercising or training, female athletes, as well as coaches, need to be made aware of their biomechanical differences that can put them at a disadvantage, if 

certain precautions are not taken, to ensure that the risk of ACL tears are decreased as much as possible. Families such as the Morgans, whose lives revolved around their three children and the sports they played, faced three ACL tears in under two years, both from their daughters during their soccer games, resulting in three surgeries and months of rehabilitation, which could have 

possibly been prevented. Receiving proper education and training techniques through a prevention program will not only keep female athletes on the field for longer, but it will increase their strength and overall ability as a player on the field, and lead to a healthier lifestyle off the field.
