When the athletic community hears the phrase, “Anterior Cruciate Ligament Tear”most associated not only recognize the severity, but also cringe at the well known consequences and steps to recovery that will follow the injury. The Anterior Cruciate Ligament (ACL) is one of the smallest of the four ligaments located in a position that runs diagonally through the middle of the knee. It functions as a ligament that prevents the Tibia from sliding out in front of the Femur, as well as provide stability to the knee when undergoing rotational movements. Female Athletes that suffer from an ACL injury find themselves on a spectrum from those who suffer sprains or a partial torn ACL, resulting in physical therapy and rehabilitation, or most commonly those who suffer from a completely torn ACL, requiring medical surgery in addition to months of  physical therapy and recovery time. Reporter of NBC Sports, Mark Fein, stated, “Doctors in Philadelphia noticed a 400 percent increase in anterior cruciate ligament (ACL) injuries in teens and adolescents over the last 10 years.” Out of this statistic it was found that females on average are five times more likely to suffer the injury rather than males. The high growing rate of Anterior Cruciate Ligament injuries in teenage female athletes of todays generation and not male athletes is due to multiple risk factors categorized into two groups: Intrinsic or Extrinsic risk variables. 

Intrinsic variables that correlate to an Anterior Cruciate Ligament injury include those inherent to the individual female athlete such as the anatomical geometry of ones knee itself. When comparing the geometry of females versus males bodies one finds not only that the Intercondylar notch (the groove in the femur where the ACL runs through) tend to be narrower, but the ACL tends to be smaller itself causing females to be more prone to injury.  A majority of studies conducted and analyzed by The US National Library of Medicine National Institutes of Health found a relationship between notch width and risk of suffering an ACL injury. “As Intercondylar notch width decreases, an increase in ACL injury risk is observed.” (Sports Health) 

The increased risk of Anterior Cruciate Ligament injuries in females rather thanks males has a lot to do with the differences in their Pelvis width and shape of thigh bone structure as well.  Typically women are found to have a wider pelvis, which makes the thigh bones angle downward more sharply than males. This phenomenon puts strain on the quadriceps femoris muscle angleis, also known as the term “Q-angle”. The larger the “Q-angle” in a female athlete, the greater the pressure that is applied to the medial aspect, or inside of the knee, between the femur and tibia which if pushed hard enough can cause the ACL to give and tear . Furthermore, the alignment of a females knee when she lands from a jump is predisposed based on her Q-angle, resulting in an inward knock-kneed movement when landing. “Some researchers believe that this inward bend may predispose women to land improperly and increase risk of ACL injuries.” (momstream.com) 

Muscular factors that surround the outsides of the knee and regulate the way the knee works to protect the joint also play a huge role in increasing risk in female athletes to tear their Anterior Cruciate Ligament. The two main muscles that play a role in protecting the reminisce of the knee ligaments are the Quadriceps and Hamstrings. The Quadriceps/ Hamstring strength ratio found in female athletes is usually significantly unbalanced, while male athletes tend to have equal strength throughout their quads and hamstrings. “Athletes with smaller H/Q strength ratios are thought to preferentially use their quadriceps muscles to stabilize the knee during dynamic activities.”(humankinetics.com) Most female athletes show an overly strong quadriceps muscle, and have poor/weak hamstring strength. If the hamstring can not support the power of the quadriceps, stress will push down on the ACL leading to possible injury. Another factor surrounding the knee joint that effects ACL injury is the laxity (give) of female athletes knee ligaments. Women’s ligaments tend to have more give than males. “What one doctor characterized as ligament dominant rather that muscular dominate.” (momstream.com) The joint motion shown from female athletes, in addition to their greater flexibility plays a significant factor in the higher rate of ACL in women. When a female athlete shows greater flexibility in her knee it can lead her body to stretch until hyperextension of the knee occurs, leading to injury. The cognitive disadvantage female athletes show of having slower reflex times than male athletes also effects female athletes risk. “Research shows that the muscles stabilizing the knee may take a millisecond longer to respond in women than in men. Scientists suspect that this small difference in contraction time also leads to a higher rate of injury.” (momstream.com) 

Unfortunately, hormonal changes and issues in females have an affect of increased susceptibility to injury as well. Researchers see a higher percentage of  female athletes in puberty based teenage years tearing their Anterior Cruciate Ligament rather than those in pre puberty years for multiple reasons. During Puberty a females body grows and changes very rapidly throwing the knee ligaments and muscles off from their norm creating a greater risk of malfunction and injury. Estrogen levels found during ones menstrual cycle has also been seen to correlate into ACL injury. “Estrogens increased during the menstrual cycle, increase the laxity in connective tissue, and may make the female athlete more susceptible to an injury during those times.” (dynamicchiropractic.com) Increased estrogen also allows female athletes to have greater endurance, which will allow them to perform longer and as females have a greater body fat percentage than males it adds greater stress to the joints. The topic of increased Anterior Cruciate Ligament injuries during a females menstrual cycle versus off of it is still a very controversial subject where some researchers prove it true, while others such as the 2007 article in The British Journal of Sports Medicine who did not find any conclusive evidence linking ACL injury increases to a predictable time in a female athlete’s menstrual cycle. 

Extrinsic factors are ones external to the female athlete and can be manipulated through change. These factors can be the certain mechanisms performed by the female athletes, whether contact or non contact injuries take place. Out of all Anterior Cruciate Ligament injuries seventy percent are from non-contact movements, and “93% of ACL injuries in the female athlete are non-contact.” (agilitydoctor.com)  Landing from a jumping movement is one of the main non-contact athletic mechanism researchers have seen in ACL tears and occurs seven times more frequently in todays  sporting games due to this generations intensity. When male athletes land from a jump they do so in a lower position with their knees bent, however female athletes on the other hand tend to land and plant in a more upright position with less bend in their knees, and their knees rotated pointed inward. Another issue in female athletes landing mechanism is seen in how their feet land. One of the major reasons a female athlete suffers injury is due to the fact they tend to land in a flat-footed position, as opposed to landing on the balls of their feet where their calves should support them. "If the calf muscles are not absorbing the force, and if the knee is not in the proper position, the knee buckles and tears the ACL," explains Dr. Boden. Cutting movements and sudden fast change sin direction are the next non-contact athletic mechanisms most seen in ACL injuries. Female athletes who injury their ACL during these movements do so by cutting their bodies faster than their knees can turn and change directions. This movement leaves their bodies locked into position, stiff and straight legged, and prone to greater risk of tearing an ACL. 

Three out of every ten Anterior Cruciate Ligament injuries are due to extrinsic contact athletic player to player hits such as being clipped from behind, knee to knee hits, or being struck from an angle while the foot is firmly planted in the ground. (mydoctor.kaiserpermanente.org) Contact ACL injuries are a large section of the percentage of increase in numbers seen in female athletes of todays generation. This is due to the dramatical increase in speed, power, and intensity displayed by female athletes over the past decade. Contact ACL injury percentage is on the rise as well due to the over-competitiveness of young athletes aspiring to be the best of the best rather than play for the enjoyment of the game. Parents and coaches of todays generation push their athletes into overbearing amounts of year round training for one specific sport, allowing no time for rest or recovery for the bodily muscular structures. Furthermore, the young athletes usually lack a full understanding of the risks they are put at stake competing at such a high level without the proper teaching of ACL safety precautions. The “I want to be like him/her” mentality looking towards professional athletes has taken over our societal norm and produced highly competitive female athletes prone to greater risk of ACL tears and other injuries. I personally have experience with the percent of female athletes who tear an ACL through a contact hit, when another player on the opposing team and myself went into a slide tackle which when hit by the opponents cleat into my knee, dislocated my knee cap. I went on to put my knee cap back into place and finishing the match later learning that when I made that decision to fix my knee myself I did so incorrectly further tearing my ACL.

Other Extrinsic risk factors include weather, type and condition of surface played, footwear, and sport played. Weather conditions have been related to an increase in Anterior Cruciate Ligament injuries when seen that the weather is wet and rainy. This type of weather reduces friction between the athletes shoe and playing surface. Lack of friction increases the likelihood of non contact injuries, while this specific weather type causes the players to slip and slide increasing the chance of contact injuries from player to player. Different types of footwear worn during athletic sports and competitions can increase or decrease friction as well. “High degrees of rotational traction associated with athletic footwear can increase the risk of non contact lower extremity injury.” (lermagazine.com) In my experience watching ACL tears from the perspective of soccer female athletes that have suffered knee injuries respond better when wearing turf or indoor shoes rather that cleats with studs when playing. This is because the cleats studs stick directly into the ground causing a greater risk of the athletes foot getting caught in the ground when the player is trying to cut and turn to quickly. When this occurs an athlete usually feels a popping sensation and suffers a non contact ACL tear. 

The type of surface played effects rate of Anterior Cruciate Ligament injury based on what athletic sport is being played. For example, soccer players are twice as likely to tear their ACL when playing on artificial turf rather than natural grass, but their is no correlation when looking at football players. (lermagazine.com) Looking at it through a soccer perspective this could be because the game is played towards the ground with a lot of cutting and turning, and tackling towards the lower half of ones body, so getting an athletes foot stuck in turf is more dangerous and detrimental. “Some have observed increased rates of injury when soccer clubs install artificial turf at their home venue.” (lermagazine.com) Other sports where surface type influence injury rate include tennis. In one study researchers found more injuries when played on grass and hard courts rather than on clay courts. In Team Handball the ACL injury rate for specifically female athletes was significantly higher on rubber artificial floors rather than wooden floors. “Confounding factors related to artificial sports surfaces include the infill used, the fiber structure of the artificial surface, the maintenance or contamination of the surface, the surface hardness, infill compaction and surface wear, surface temperature, surface moisture, and the type of grass/soil comprising the natural grass surfaces.” (lermagazine.com) Any of these surface properties can influence an athletes risk of ACL tear. 

Some people might argue that male athletes have a higher rate of ACL injury due to many reasons such as harder physical play and competitiveness resulting for the majority of contact ACL injuries. While they do have that higher percentage over females boys are at an advantage of preventing ACL tears from an early age. Boys have been historically taught in activities that increase their strength, agility, and coordination from the start giving females a disadvantage when they begin sports. Male athletes are also typically more hamstring dominate. “These large muscles on the back of the thigh are used to flex the knee and mimic the function of the ACL by preventing the shin bone from sliding forward.” (agilitydoctor.com) Hamstring dominate helps prevent the knee, while when looking at female athletes one sees they are almost always quadriceps dominate. As non contact athletic mechanisms go male athletes are more technical in landing and cutting in a lower position keeping their knees bent instead of strait legged. Male Athletes also tend to have stronger core strength than female athletes which helps stabilize their body when competing in rigorous sports  This shows why even though male athletes suffer from more contact related ACL tears, female athletes still are in more increased danger from the beginning of injuring their ACL.

There are specific things that can be done to help prevent female athletes from tearing their Anterior Cruciate Ligament such as following a specific neuromuscular strength and conditioning adjustment program. Proper leg muscle strengthening, training female athletes to rely more on hamstring strength rather than quadricep strength, and strengthening female athletes core to increase balance. Neuromuscular training, which includes having female athletes focus more on proper balance when using speed and agility. Coaching them to jump and land correctly keeping their knees bent instead of strait legged. Finally helping female athletes find proper footwear and orthotics for their body and sport played, “the amount of traction or "grippiness" of athletic shoes needs to fall within an optimal range that minimizes rotational friction to avoid injury yet optimizes transitional friction to allow peak performance in activities such as cutting and stopping.” (momstream.com) Preventing future ACL tears and injuries in female athletes heavily focuses as well towards the coaching of the athletes from the coach him/herself. Having a coach that recognizes the importance of recovery time and the rest the body needs not to get overly exhausted and lazy in safe play. Coaches need to stop having a “push through the pain” mentality towards their athletes to keep them safe on and off the field.

The rise in Anterior Cruciate Ligament injuries in female athletes rather than males is currently drastic and will continue to rise if precautions are not taken. Female athletes are already at a disadvantage from multiple intrinsic variables that do not apply to their male athlete counterparts, but with the proper training it is possible to stop the rise in injuries and get on the same playing field as the male athletes. 