[Lauren Cowley is currently a senior at the University of Mount Olive and will graduate in May 2017. She is an Exercise Science Major, and a former NCAA DII Soccer Player. She is currently an Athletic Development Intern at Athletic Lab.]
Season ending, and even career ending injuries have, unfortunately, been frequent and perhaps even common throughout my exposure in collegiate soccer. Fortunately, I was ?lucky? enough to avoid anything further than multiple concussions throughout my playing career. However, some of my teammates were not. In being a female soccer player, or even a soccer player, anterior cruciate ligament (ACL) injuries were almost expected and injury prevention exercises were frequently done in order to prevent them as much as possible. However, what always interested me was, why? Why are women more likely to tear their ACL than males? So I decided to review and research the impact of gender on the likelihood of injury. My first finding was that it is not just ACL injuries that can be predisposed by gender. Achilles tendon ruptures, stress fractures, and multiple other ?common? sporting injuries can all be impacted by gender.
Differences in mechanics between genders are one explanation. The anatomical structure of the human body plays a great role in biomechanical alignment and function, thus why the difference in the male and female anatomical structures can lead them pre-disposed to certain injuries. One example of this would be in the sport of running, women have around a 50% increased risk of common injuries such as patella femoral pain syndrome, plantar fasciitis and iliotibial band syndrome (Taunton 2002). This appears to be due to greater peak hip adduction and internal rotation, and greater knee abduction and ankle eversion throughout each running stance phase in women compared to men. Women also demonstrate significantly greater negative work in the hip frontal and transverse plane than men (Ferber, McClay Davis, & Williams III, 2003). In turn, this all results in increased valgus stress of the knee, which abnormally displaces forces onto ligaments and other knee and hip supporting structures, increasing risk of injury. This gender pre-disposal can be prevented through women wearing specific footwear that reduces ankle eversion, and thus decreases the valgus stress at the knee (Sinclair et al., 2012).
In terms of mechanics when landing from jumping, women characteristically land with a more upright landing posture, utilizing larger hip and ankle range of motion compared to men. This landing position for women leads to greater energy absorption and greater knee extensors peak powers. However, when the onset of fatigue occurs, the eccentric muscle control required for this greater energy absorption lacks, and force becomes directly applied to the knee, posing greater risk of injury, specifically the ACL (Decker et al., 2003). Quick turns and direction changes are also impacted by gender. It is up to six times more likely for women to incur an injury in sports that require quick turns and direction changes than their male counterparts (Pollard, Davis, & Hamill, 2004).
The risk of developing stress fractures may be significantly higher in women than men as a result of anatomical disadvantages. Compared to men, women have wider pelvic breadths (Beck et al., 2000). This wider pelvis increases the stress on the hips and knees and on the lower leg and foot, as it alters the angular tilt of them, and thus negatively alters loading strains (Bijur, 1997). Through more prominent hip adduction as a result of the wider pelvic breadths, greater stress is place on the knee and tibia (Pohl et al., 2008). Therefore, making a female more susceptible to developing a stress fracture.
Gender differences in neuromotor control is another reason for specific gender pre-disposal to injury. The most common injury that reflects significant differences in neuromuscular control between males and females is the ACL injury. Women are at least 4-6 times at risk of ACL injury than their male counterparts, whilst women with increased dynamic valgus and great abduction loads are at increased risk of ACL injury (Hewett, 2005). Women?s lack of neuromuscular control when muscular fatigue onsets and increase in anterior shear at the knee when compared to males, also increases the risk of ACL injuries in women (Kernozek, Torry, & Iwasaki, 2008). In terms of using this knowledge for injury prevention, Mandelbaum (2005) found that by incorporating a neuromuscular training program for female soccer players prior to the season beginning, it resulted in a decrease in ACL injuries by 88% and in ACL tears by 74% (Mandelbaum, 2005).
Another explanation for gender?s role in pre-disposal to certain injuries may be hormonal differences between men and women. Sex hormones, e.g. estrogen and progesterone, cause an alteration of gene expression in soft tissues. Therefore sex hormones may influence the structure and function of tendons, particularly the achilles tendon. Estrogen reduces fibroblast biosynthesis, and could possibly decrease collagen density, which could in turn decrease tendon resistance to injury (Lee et al., 2004). Elevated endogenous estrogen levels in females have also been correlated with decreased collagen rates of synthesis, which can lead to reduced tendon cross-sectional area (Miller et al., 2006) which in turn, can increase risk of injury by reducing the tendon?s ability to adapt to loading upon it.
Sex hormones have also resulted in ligamentous laxity being found to be more dominant in females than males. This appears to be as a result of the women?s menstrual cycle, due to peak levels of estrogen and progesterone (Harmon & Ireland, 2000). ACL rupture incidence is found to be at its highest in females during the ovulation phase of their menstrual cycle, as that is when estrogen levels are at their peak (Wojtys et al., 1998). Wojtys et al. (2002) also discovered that oral contraceptive use decreases the occurrence of injury observed during this ovulation phase (Wojtys et al., 2002).
Surprisingly, whilst it seems that women are more susceptible to some sporting injuries, the incidence of the achilles tendon ration from female to male of 18/100,000 (Karaaslan et al., 2016). One of the main reasons for this is due to a lower force and loading rate in women compared to men, as women have an increased tendency to use a rearfoot strike pattern than men (Bertelsen et al., 2013). Alongside this, collagen fascicles from men reach much higher levels of ultimate stress than women?s collagen fascicles (Abate et al., 2010). Chronic estrogen exposure, predominately in women, has also been discovered to decrease the likelihood of an achilles tendon strain (Wojtys et al., 2002), another reason as to why the incidence of the achilles tendon is significantly higher in men than women.
In terms of applying this, knowing how a specific gender is more susceptible to certain injuries than others, effective injury prevention can be done in order to prevent injury as much as possible. Through identifying neuromuscular imbalances, effective injury prevention exercises can be completed to ensure less significant imbalances. This can be done through training both feet when changing direction, rather than just one dominant foot. Working on jumping landing techniques, to make them safer, is another way in which injury can be prevented, as well as weight-lifting programs which work on improving strength in specific muscles, such as the hamstrings in order to decrease the quadriceps to hamstring ratio. This ensures repetitive movement, which in turn can enhance skills needed to decrease injury.
Through prior research conducted, it is clear that gender plays a role in the predisposition to certain injuries. Through this knowledge, effective injury prevention techniques can be developed in order to attempt to prevent injuries occurring as a result of gender pre-disposal. However, external implications need to be also taken into consideration, such as footwear, playing surface or playing conditions, and even the sport being played. Whilst effective injury prevention programs may take place, these external implications also play a factor in, if, how, or why an athlete becomes injured and the extensiveness of the injury. Therefore, a coach, and even an athlete may want to take gender, and further considerations into account for the risk of becoming injured, and effective ways to prevent this occurring.
References:
Abate, M., Schiavone, C., Pelotti, P., & Salini, V. (2010). Limited Joint Mobility in Diabetes and Ageing: Recent Advances in Pathogenesis and Therapy. International Journal of Immunopathology and Pharmacology, 23(4), 997-1003.
Beck, T., Ruff, C., Shaffer, R., Betsinger, K., Trone, D., & Brodine, S. (2000). Stress fracture in military recruits: gender differences in muscle and bone susceptibility factors. Bone, 27(3), 437-444.
Bertelsen, M. L., Jensen, J. F., Nielsen, M. H., Nielsen, R. O., & Rasmussen, S. (2013). Footstrike patterns among novice runners wearing a conventional, neutral running shoe. Gait & Posture, 38(2), 354-356.
Bijur, P. E. (1997). Comparison of Injury During Cadet Basic Training by Gender. Archives of Pediatrics & Adolescent Medicine, 151(5), 456.
Decker, M. J., Torry, M. R., Wyland, D. J., Sterett, W. I., & Richard Steadman, J. (2003). Gender differences in lower extremity kinematics, kinetics and energy absorption during landing. Clinical Biomechanics, 18(7), 662-669.
Ferber, R., McClay Davis, I., & Williams III, D. S. (2003). Gender differences in lower extremity mechanics during running. Clinical Biomechanics, 18(4), 350-357.
Harmon, K. G., & Ireland, M. L. (2000). GENDER DIFFERENCES IN NONCONTACT ANTERIOR CRUCIATE LIGAMENT INJURIES. Clinics in Sports Medicine, 19(2), 287-302.
Hewett, T. E. (2005). Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes: A Prospective Study. American Journal of Sports Medicine, 33(4), 492-501.
Karaaslan, F., Mermerkaya, M. U., ??rakl?, A., Karao?lu, S., & Duygulu, F. (2016). Surgical versus conservative treatment following acute rupture of the Achilles tendon: is there a pedobarographic difference? Therapeutics and Clinical Risk Management, Volume 12, 1311-1315.
Kernozek, T. W., Torry, M. R., & Iwasaki, M. (2008). Gender Differences in Lower Extremity Landing Mechanics Caused by Neuromuscular Fatigue. The American Journal of Sports Medicine, 36(3), 554-565.
Lee, C., Liu, X., Smith, C. L., Zhang, X., Hsu, H., Wang, D., & Luo, Z. (2004). The combined regulation of estrogen and cyclic tension on fibroblast biosynthesis derived from anterior cruciate ligament. Matrix Biology, 23(5), 323-329.
Mandelbaum, B. R. (2005). Effectiveness of a Neuromuscular and Proprioceptive Training Program in Preventing
Anterior Cruciate Ligament Injuries in Female Athletes: 2-Year Follow-up. American Journal of Sports Medicine, 33(7), 1003-1010.
Miller, B. F., Hansen, M., Olesen, J. L., Schwarz, P., Babraj, J. A., Smith, K., ? Kjaer, M. (2006). Tendon collagen synthesis at rest and after exercise in women. Journal of Applied Physiology, 102(2), 541-546.
Niixius, S. A., Nilsson, B. E., & Westlin, N. E. (1976). The Incidence of Achilles Tendon Rupture. Acta Orthopaedica Scandinavica, 47(1), 118-121.
Pohl, M. B., Mullineaux, D. R., Milner, C. E., Hamill, J., & Davis, I. S. (2008). Biomechanical predictors of retrospective tibial stress fractures in runners. Journal of Biomechanics, 41(6), 1160-1165.
Pollard, C. D., Davis, I. M., & Hamill, J. (2004). Influence of gender on hip and knee mechanics during a randomly cued cutting maneuver. Clinical Biomechanics, 19(10), 1022-1031.
Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin. (2002). New England Journal of Medicine, 346(6), 393-403.
Sinclair J, Greenhalgh A, Edmundson CJ, Brooks D, Hobbs SJ. Gender differences in the kinetics and kinematics of distance running: implications for footwear design. International Journal of Sports Science and Engineering 2012; 6:2: 118-128
Taunton, J. E. (2002). A retrospective case-control analysis of 2002 running injuries. British Journal of Sports Medicine, 36(2), 95-101.
Wojtys EM, Huston LJ, Lindenfeld TN, et al. Association between the menstrual cycle and anterior cruciate ligament injuries in female athletes. Am J Sports Med 1998;26(5):614-619.
Wojtys EM, Huston LJ, Boynton MD, et al. The effect of the menstrual cycle on anterior cruciate ligament injuries in women as determined by hormone levels. Am J Sports Med 2002;30(2):182-188.
John Grace
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- Overtraining – How Fatigue Can Lead to Increased Risk of Injury by Lauren Cowley - March 2, 2017
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- The Role of Gender in Pre-Disposal to Injury by Lauren Cowley - February 10, 2017