ACL Tears In Female Athletes Research Paper
Biology 100 – Section 005
November 4, 2013
ACL Tears in Female Athletes
ACL TEARS IN FEMALE ATHLETES
The Anterior Cruciate Ligament (ACL) found in the knee connects the femur (thigh bone) to the tibia (shin) and provides stability to the knee. The ACL prevents the tibia from shifting too far forward and from rotating too far inward under the femur. The recent increase of this injury has parents, athletes, doctors, and coaches in fear. Athletes and parents fear the injury to due the expensive surgery, and the difficult physical emotional and mental recovery. The classic tearing of the Anterior Cruciate Ligament has no contact involved and occurs when an athlete is stopping suddenly, cutting, twisting, and jumping. The athlete …show more content…
will normally here and feel a pop as their knee gives out and they fall to the ground. On occasion the athlete may try to continue playing on the injury but normally the knee will buckle and they will begin to feel pain. ACL injuries annually rise to 200,000 cases with 100,000 of these knees are reconstructed. The problem is that the injury is 2 to 8 times more common in women. Why? Why do women have this injury occur so much more than men? Women have many structural and hormonal differences than men thus, resulting in a higher number of ACL injuries. Women also move differently than men and this isn’t to their benefit. Structural, mechanical, and hormonal differences are the three main causes to women tearing this ligament more than men. To know these differences and possible prevention of the injury one must take a deeper look into the science of the matter.
Men and women are differently anatomically and this is problematic for female athletes giving them a higher risk of injury. According to Griffin (1) Females have a higher risk of being injured. NCAA statistics found that female athletes are 2-8 times more likely to sustain an ACL injury playing sports. Several factors are speculated to increase risk of ACL injury in females including lower extremity alignment (wider pelvis, knee valgus, foot pronation), joint laxity, hamstring flexibility, muscle development. According to Quinn (2) The most obvious anatomic difference between men and women that may lead to ACL injuries is a wider pelvis in women then men. This difference results in a wider "Q-angle," or quadriceps angle. This is the angle at which the femur meets the tibia. It is thought that this increased angle places more stress on a woman 's knee joint, which makes it less stable than a man 's knee joint. This lack of stability causes the ACL to tear and the knee to buckle when female athletes land, cut, or twist with too much power or speed. Other than wider hips another anatomical difference between men and women is that women have weaker quadriceps. Women have less developed thigh muscles, making the knee more dependent on the ligaments for stability resulting in more knee injuries especially ACL’s. In addition, Hirst et al (3) Women do not have as much muscle as men in their quardriceps and hamstring even after their muscle strength has been normalized for body weight. Because knee stability depends on the strength of the surrounding muscles (primarily hamstrings and quadriceps) women are more prone to ACL injuries. There are many anatomical differences between men and women that put at a higher risk then men for tearing knee ligaments but the ACL in particular. The anatomical differences are not the only reason for this injury to women. The way they move and the mechanics of their athletic maneuvers are another reason why the knee gives out and the ACL tears.
When women and men compete in sports, at a high level of competition, they have almost equal twisting and loading forces placed on their knees.
However, as discussed before women have less muscle strength. Other than muscular or other anatomical differences, Women also have different mechanically than men. Women tend to make athletic maneuvers with more of a straight leg. The mechanics that women use during cutting, twisting, pivoting, and stopping contribute to the higher risk of injury. Women perform these maneuvers in an erect manner. As women make these sharp turns or cuts they tend to have their backs in a more upright position and they do not bend their legs as much as men. Thus, leading to less stability on the knee and a greater chance of tearing a ligament. Men normally have developed stronger muscles and better coordination when competing at high level sports and they move in a more athletic way than women. Men bend their knees and lower their center of gravity to increase balance. This is accomplished by bending the knees more and using the hamstring muscles to absorb more of the force applied when jumping, cutting, and twisting taking more pressure of their knee thus decreasing their risk of an ACL injury. Another major reason any athlete tears their ACL is because of flat-footed landing. This occurs when an athlete jumps, or cuts and instead of landing on the balls of their feet they land flat-footed. Landing on the balls of their feet with a bent knee lets the …show more content…
muscles absorb the force instead of the ligaments in their knee. Women especially land on their feet flat-footed and the knee buckles causing the ACL to tear because of the lack of muscular strength. Men and women are very hormonally different and this difference is another reason women are more likely to tear their ACL. In addition, Hewitt et al (4) Boys tend to land and cut in a lower position with the knees bent. Girls tend to land and plant their feet in a more upright position with less of a bend and some inward rotation in the knee. This is the position that puts a lot of stress on the ACL and increases the risk of tearing it. Although there is still some debate surrounding the exact reasons why this might occur, the increased risk for female athletes is significant and real. In addition to the way women move and perform athletic maneuvers differently than men they are also very different hormonally adding to their risk of injury.
Hormones play a very significant role in women’s susceptibility to ACL tears and other knee injuries. It’s been found that the menstrual cycle increases the risk of female athletes tearing their ACL even higher. Wojtys suggests (5) that the menstrual cycle might play a part in the occurrence of ACL tears in women. This cycle is based on the coordination between the endocrine and the hypothalamus, the pituitary gland, and the ovaries. These centers communicate with hormones through the circulatory system. Among the hormones that affect tissues and systems far away from the ovarian follicles are estrogen, progesterone, and relaxin. The effects of progesterone are not well understood, but it known to act as an anesthetic for the central nervous system. Relaxin has been found to significantly decrease collagen tension. Estrogen has the most influence on the body the menstrual cycle. Estrogen affects the strength of soft tissue, and the function of muscles. Estrogen also relaxes joints and reduces the strength. The most important discovery was that women had an increased incidence of ACL injury during the ovulatory stage of their monthly cycle. In this stage there is a dramatic increase of estrogen production. This is when most non-contact ACL injuries occur in women. Wojtys also stated, (5) Men do not experience the hormonal cycle and surges that women do. As a consequence, men do not have periodic increases in estrogen, progesterone, and relaxin that affect soft tissue strength, diminish collagen tension, and anesthetize the central nervous system. Women athletes are tearing their ACL’s because their natural hormones are making their ligaments and muscles more relaxed and weaker. Women are at a higher risk of tearing their ACL because of the structural, mechanical, and hormonal differences they have than men, but there are many types of prevention you can take to decrease that risk.
There is no absolute prevention of ACL tears or any injury at that.
There are ways to lower the risk of the injury and this should be a necessary step to all athletes especially females. There are 3 ways to help prevent the injury and lessen the risk of it actually occurring. Hormonal prevention, Anthropometric prevention, neuromuscular and proprioceptive training programs are ways to help lower the risk of injury. Hormonal prevention in females can decrease the risk of an ACL tear by taking birth control or other contraceptives that balance hormones. Female hormones of estrogen, relaxin, and progesterone have all been known to affect the knee ligaments. Women taking oral contraceptives have had a much lower number of ACL injuries than those who were not but putting women on oral contraceptives is not a definite way to prevent these injuries. Putting a young female athlete on hormones to control estrogen, relaxin, and progesterone strictly for injury prevention is not a great idea because of the other side effects that may occur. Anthropometric measurement prevention is a way to prevent knee injuries like ACL tears in women only after the injury has already occurred. When reconstructing the ACL some surgeons perform a notchplasty that increases the width of the femoral notch in women. This is the notch on the femur where the ACL slides through. Making the hole bigger lessens the risk of a re-tear. This procedure is very costly and quite invasive. The last way of prevention
is neuromuscular and proprioceptive training programs. Recent studies have shown that these training programs have decreased the amount of ACL tears in women athletes. According to Mandelbaum et al (6) The Prevent Injury and Enhance Performance (PEP) cohort study involved 1,041 female soccer players between 14 and 18 years of age. The control group in this study consisted of 1,905 female soccer players. The active participants viewed a videotape that consisted of 3 warm-up activities, 5 special techniques for stretching for the lower extremities and trunk, 3 soccer-specific agility drills, 5 plyomeric activities, and 3 strengthening exercises. The emphasis of this program was on proper technique in activities such as “soft landing” with deep hip and knee flexion. The number of ACL tears decreased due to the training of the muscles that are used in sports. There is no way to absolutely prevent and ACL tear but many steps can be taken so women that are at a higher risk can decrease the chance of this injury occurring.
All in all, women have an increased rate of ACL injuries compared to men. The NCAA conducted a study over a five-year period and found that the injury rate for female soccer players was more than double than males. This is because of many factors. First because of the structural differences between men and women, such as: Muscular strength in men is greater than women thus taking away force of athletic maneuvers away from the knee. Also women have wider hips causing the knee to have more rotation resulting in the buckling and tearing of knee ligaments. The second reason of women being more at risk for ACL injuries is because of the incorrect performance of high risk maneuvers. Women tend to cut, jump, and twist in ways without bending their knees and lowering their center of gravity. Their knees take the force from these actions and tend to give out and tear. The last factor in differences between men and women is the hormonal difference. Hormones such as estrogen, progesterone, and relaxin cause ligament to loosen up and become relaxed resulting in more ACL tears. Many steps have been taken in prevention of ACL tears through hormonal prevention, anthropometric prevention, neuromuscular and proprioceptive training programs. The most effective prevention has been the neuromuscular and proprioceptive training programs because they strengthen the muscles around the knee, learning how to trigger those muscles faster for stability, and teaching women corrective ways to perform high-risk maneuvers. All these are have proven to decrease the chance of female athletes tearing their Anterior Cruciate Ligaments.
REFERENCES
1. Griffin LY. Noncontact Anterior Cruciate Ligament Injuries: Risk Factors and Prevention Strategies. Journal of the American Academy of Orthopedic Surgeons. 2000;8:141-150.
1 2. About.com [homepage on the Internet]. ACL Injuries In Female Athletes [updated 2012 October 12; cited 2013 Nov 3]. Available from: http://sportsmedicine.about.com/od/women/qt/Acl-Injury-And-Female-Athletes.htm
2
1 3. Hirst, HE, Armeau E., Parish T. Recognizing anterior cruciate ligament tears in female athletes. The Internet Journal of Allied Health Services and Practice. Jan 2007, Volume 5 Number1.
2
1 4. Hewett, Timothy E., PhD, Myer, Gregory D, MS, CSCS, and Ford, Kevin R., MS, Anterior Cruciate Ligament Injuries in Female Athletes, Part 1, Mechanisms and Risk Factors, The American Journal of Sports Medicine, Vol. 34, No. 2, 299-311, 2006.
5. Wojtys, E. M., Huston, L J., Lindenfeld, T. N., Hewett, T. E., & Greenfield, M. V. Association between the menstrual cycle and anterior cruciate ligament injuries in female athletes, The American Journal of Sports Medicine, 26, 614-618. 1998.
6. Mandelbaum, B. R., Silvers, H. J., Watanabe, D. S., Knarr, J. F., Thomas, S.D., & Griffin, L. Y., (2005, July 1). Retrieved January 17, 2006, from http://ajs.sagepub.com/cgi/content/full/33/1003
November 4, 2013
ACL Tears in Female Athletes
ACL TEARS IN FEMALE ATHLETES
The Anterior Cruciate Ligament (ACL) found in the knee connects the femur (thigh bone) to the tibia (shin) and provides stability to the knee. The ACL prevents the tibia from shifting too far forward and from rotating too far inward under the femur. The recent increase of this injury has parents, athletes, doctors, and coaches in fear. Athletes and parents fear the injury to due the expensive surgery, and the difficult physical emotional and mental recovery. The classic tearing of the Anterior Cruciate Ligament has no contact involved and occurs when an athlete is stopping suddenly, cutting, twisting, and jumping. The athlete …show more content…
will normally here and feel a pop as their knee gives out and they fall to the ground. On occasion the athlete may try to continue playing on the injury but normally the knee will buckle and they will begin to feel pain. ACL injuries annually rise to 200,000 cases with 100,000 of these knees are reconstructed. The problem is that the injury is 2 to 8 times more common in women. Why? Why do women have this injury occur so much more than men? Women have many structural and hormonal differences than men thus, resulting in a higher number of ACL injuries. Women also move differently than men and this isn’t to their benefit. Structural, mechanical, and hormonal differences are the three main causes to women tearing this ligament more than men. To know these differences and possible prevention of the injury one must take a deeper look into the science of the matter.
Men and women are differently anatomically and this is problematic for female athletes giving them a higher risk of injury. According to Griffin (1) Females have a higher risk of being injured. NCAA statistics found that female athletes are 2-8 times more likely to sustain an ACL injury playing sports. Several factors are speculated to increase risk of ACL injury in females including lower extremity alignment (wider pelvis, knee valgus, foot pronation), joint laxity, hamstring flexibility, muscle development. According to Quinn (2) The most obvious anatomic difference between men and women that may lead to ACL injuries is a wider pelvis in women then men. This difference results in a wider "Q-angle," or quadriceps angle. This is the angle at which the femur meets the tibia. It is thought that this increased angle places more stress on a woman 's knee joint, which makes it less stable than a man 's knee joint. This lack of stability causes the ACL to tear and the knee to buckle when female athletes land, cut, or twist with too much power or speed. Other than wider hips another anatomical difference between men and women is that women have weaker quadriceps. Women have less developed thigh muscles, making the knee more dependent on the ligaments for stability resulting in more knee injuries especially ACL’s. In addition, Hirst et al (3) Women do not have as much muscle as men in their quardriceps and hamstring even after their muscle strength has been normalized for body weight. Because knee stability depends on the strength of the surrounding muscles (primarily hamstrings and quadriceps) women are more prone to ACL injuries. There are many anatomical differences between men and women that put at a higher risk then men for tearing knee ligaments but the ACL in particular. The anatomical differences are not the only reason for this injury to women. The way they move and the mechanics of their athletic maneuvers are another reason why the knee gives out and the ACL tears.
When women and men compete in sports, at a high level of competition, they have almost equal twisting and loading forces placed on their knees.
However, as discussed before women have less muscle strength. Other than muscular or other anatomical differences, Women also have different mechanically than men. Women tend to make athletic maneuvers with more of a straight leg. The mechanics that women use during cutting, twisting, pivoting, and stopping contribute to the higher risk of injury. Women perform these maneuvers in an erect manner. As women make these sharp turns or cuts they tend to have their backs in a more upright position and they do not bend their legs as much as men. Thus, leading to less stability on the knee and a greater chance of tearing a ligament. Men normally have developed stronger muscles and better coordination when competing at high level sports and they move in a more athletic way than women. Men bend their knees and lower their center of gravity to increase balance. This is accomplished by bending the knees more and using the hamstring muscles to absorb more of the force applied when jumping, cutting, and twisting taking more pressure of their knee thus decreasing their risk of an ACL injury. Another major reason any athlete tears their ACL is because of flat-footed landing. This occurs when an athlete jumps, or cuts and instead of landing on the balls of their feet they land flat-footed. Landing on the balls of their feet with a bent knee lets the …show more content…
muscles absorb the force instead of the ligaments in their knee. Women especially land on their feet flat-footed and the knee buckles causing the ACL to tear because of the lack of muscular strength. Men and women are very hormonally different and this difference is another reason women are more likely to tear their ACL. In addition, Hewitt et al (4) Boys tend to land and cut in a lower position with the knees bent. Girls tend to land and plant their feet in a more upright position with less of a bend and some inward rotation in the knee. This is the position that puts a lot of stress on the ACL and increases the risk of tearing it. Although there is still some debate surrounding the exact reasons why this might occur, the increased risk for female athletes is significant and real. In addition to the way women move and perform athletic maneuvers differently than men they are also very different hormonally adding to their risk of injury.
Hormones play a very significant role in women’s susceptibility to ACL tears and other knee injuries. It’s been found that the menstrual cycle increases the risk of female athletes tearing their ACL even higher. Wojtys suggests (5) that the menstrual cycle might play a part in the occurrence of ACL tears in women. This cycle is based on the coordination between the endocrine and the hypothalamus, the pituitary gland, and the ovaries. These centers communicate with hormones through the circulatory system. Among the hormones that affect tissues and systems far away from the ovarian follicles are estrogen, progesterone, and relaxin. The effects of progesterone are not well understood, but it known to act as an anesthetic for the central nervous system. Relaxin has been found to significantly decrease collagen tension. Estrogen has the most influence on the body the menstrual cycle. Estrogen affects the strength of soft tissue, and the function of muscles. Estrogen also relaxes joints and reduces the strength. The most important discovery was that women had an increased incidence of ACL injury during the ovulatory stage of their monthly cycle. In this stage there is a dramatic increase of estrogen production. This is when most non-contact ACL injuries occur in women. Wojtys also stated, (5) Men do not experience the hormonal cycle and surges that women do. As a consequence, men do not have periodic increases in estrogen, progesterone, and relaxin that affect soft tissue strength, diminish collagen tension, and anesthetize the central nervous system. Women athletes are tearing their ACL’s because their natural hormones are making their ligaments and muscles more relaxed and weaker. Women are at a higher risk of tearing their ACL because of the structural, mechanical, and hormonal differences they have than men, but there are many types of prevention you can take to decrease that risk.
There is no absolute prevention of ACL tears or any injury at that.
There are ways to lower the risk of the injury and this should be a necessary step to all athletes especially females. There are 3 ways to help prevent the injury and lessen the risk of it actually occurring. Hormonal prevention, Anthropometric prevention, neuromuscular and proprioceptive training programs are ways to help lower the risk of injury. Hormonal prevention in females can decrease the risk of an ACL tear by taking birth control or other contraceptives that balance hormones. Female hormones of estrogen, relaxin, and progesterone have all been known to affect the knee ligaments. Women taking oral contraceptives have had a much lower number of ACL injuries than those who were not but putting women on oral contraceptives is not a definite way to prevent these injuries. Putting a young female athlete on hormones to control estrogen, relaxin, and progesterone strictly for injury prevention is not a great idea because of the other side effects that may occur. Anthropometric measurement prevention is a way to prevent knee injuries like ACL tears in women only after the injury has already occurred. When reconstructing the ACL some surgeons perform a notchplasty that increases the width of the femoral notch in women. This is the notch on the femur where the ACL slides through. Making the hole bigger lessens the risk of a re-tear. This procedure is very costly and quite invasive. The last way of prevention
is neuromuscular and proprioceptive training programs. Recent studies have shown that these training programs have decreased the amount of ACL tears in women athletes. According to Mandelbaum et al (6) The Prevent Injury and Enhance Performance (PEP) cohort study involved 1,041 female soccer players between 14 and 18 years of age. The control group in this study consisted of 1,905 female soccer players. The active participants viewed a videotape that consisted of 3 warm-up activities, 5 special techniques for stretching for the lower extremities and trunk, 3 soccer-specific agility drills, 5 plyomeric activities, and 3 strengthening exercises. The emphasis of this program was on proper technique in activities such as “soft landing” with deep hip and knee flexion. The number of ACL tears decreased due to the training of the muscles that are used in sports. There is no way to absolutely prevent and ACL tear but many steps can be taken so women that are at a higher risk can decrease the chance of this injury occurring.
All in all, women have an increased rate of ACL injuries compared to men. The NCAA conducted a study over a five-year period and found that the injury rate for female soccer players was more than double than males. This is because of many factors. First because of the structural differences between men and women, such as: Muscular strength in men is greater than women thus taking away force of athletic maneuvers away from the knee. Also women have wider hips causing the knee to have more rotation resulting in the buckling and tearing of knee ligaments. The second reason of women being more at risk for ACL injuries is because of the incorrect performance of high risk maneuvers. Women tend to cut, jump, and twist in ways without bending their knees and lowering their center of gravity. Their knees take the force from these actions and tend to give out and tear. The last factor in differences between men and women is the hormonal difference. Hormones such as estrogen, progesterone, and relaxin cause ligament to loosen up and become relaxed resulting in more ACL tears. Many steps have been taken in prevention of ACL tears through hormonal prevention, anthropometric prevention, neuromuscular and proprioceptive training programs. The most effective prevention has been the neuromuscular and proprioceptive training programs because they strengthen the muscles around the knee, learning how to trigger those muscles faster for stability, and teaching women corrective ways to perform high-risk maneuvers. All these are have proven to decrease the chance of female athletes tearing their Anterior Cruciate Ligaments.
REFERENCES
1. Griffin LY. Noncontact Anterior Cruciate Ligament Injuries: Risk Factors and Prevention Strategies. Journal of the American Academy of Orthopedic Surgeons. 2000;8:141-150.
1 2. About.com [homepage on the Internet]. ACL Injuries In Female Athletes [updated 2012 October 12; cited 2013 Nov 3]. Available from: http://sportsmedicine.about.com/od/women/qt/Acl-Injury-And-Female-Athletes.htm
2
1 3. Hirst, HE, Armeau E., Parish T. Recognizing anterior cruciate ligament tears in female athletes. The Internet Journal of Allied Health Services and Practice. Jan 2007, Volume 5 Number1.
2
1 4. Hewett, Timothy E., PhD, Myer, Gregory D, MS, CSCS, and Ford, Kevin R., MS, Anterior Cruciate Ligament Injuries in Female Athletes, Part 1, Mechanisms and Risk Factors, The American Journal of Sports Medicine, Vol. 34, No. 2, 299-311, 2006.
5. Wojtys, E. M., Huston, L J., Lindenfeld, T. N., Hewett, T. E., & Greenfield, M. V. Association between the menstrual cycle and anterior cruciate ligament injuries in female athletes, The American Journal of Sports Medicine, 26, 614-618. 1998.
6. Mandelbaum, B. R., Silvers, H. J., Watanabe, D. S., Knarr, J. F., Thomas, S.D., & Griffin, L. Y., (2005, July 1). Retrieved January 17, 2006, from http://ajs.sagepub.com/cgi/content/full/33/1003