The following article was contributed by Dr. Ashley Bassett, an orthopedic sports medicine surgeon at the Orthopedic Institute of New Jersey specializing in sports injuries of the shoulder, elbow and knee. She is the Director of the Women's Sports Medicine Center at the OINJ, the only highly-specialized center for the care of female athletes in northern New Jersey.
Historically, females were excluded from most organized sports. The first modern-day Olympics held in 1896 banned female athletes due to concern that they could injure their reproductive organs. In the early 1900s, females were gradually allowed to partake in the Olympic games and while participation slowly increased over the next 50 years, female athletes remained vastly underrepresented compared to their male counterparts. It wasn’t until the advent of Title IX in 1972 that female participation in organized sports increased tremendously at the high school, collegiate and professional levels.(1) As the number of female athletes has continued to rise, sex-based differences in the prevalence and outcomes of many sports-related injuries have become apparent, relating most strongly to underlying physiology.
There are many biologic differences between males and females that lead to differing physiologic responses to exercise. In general, males have longer limbs, stronger bones, greater muscle mass and a higher proportion of type II muscle fibers – both leading to increased strength, and superior aerobic exercise capacity relating to larger heart and lung size, greater volume of red blood cells and increased hemoglobin concentration. Females have a higher proportion of type I muscle fibers – leading to less muscle fatigue and faster recovery during endurance exercise, as well as improved thermoregulation in cold temperatures relating to higher fat mass.(2)
The biologic and physiologic differences between the sexes contribute to a higher incidence of certain injuries in female athletes. In gender-comparable sports, females sustain more concussions, exhibit greater memory deficits and report more post-concussive symptoms, often requiring a longer recovery period.(3) Females have higher rates of atraumatic shoulder instability due to a combination of smaller narrower glenoids (shoulder socket), increased shoulder range of motion and greater ligamentous laxity.(4) Females are up to 10 times more likely to sustain an ACL tear, attributed to numerous hormonal, anatomic and neuromuscular factors. Females tend to land and pivot with greater knee valgus (knee bent inward), which increases stress on the ACL.(5) Relaxin, a hormone found only in females, has been shown to increase ACL laxity by breaking down collagen and is associated with increased ACL tears at higher concentrations.(6) Instability of the patella (kneecap) is more common in females due to greater ligamentous laxity, wider hips with increased Q-angle at the knee, and other anatomic variations including a shallow groove and high-riding patella.(7) Females are twice as likely to sustain an ankle sprain compared to males and have increased rates of chronic ankle instability.(8) Lastly, stress fractures occur in a nearly 2:1 female-to-male ratio in collegiate athletes, relating to less muscle mass, shorter stature and lower bone mineral density in females compared to males.(9)
It is imperative to understand these physiologic differences and predisposition to injury in order to provide optimal care to our female patients.
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Dr. Ashley Bassett is an orthopedic sports medicine surgeon at the Orthopedic Institute of New Jersey specializing in sports injuries of the shoulder, elbow and knee. She is the Director of the Women's Sports Medicine Center at the OINJ, the only highly-specialized center for the care of female athletes in northern New Jersey.
References
- National Collegiate Athletic Association. NCAA sports sponsorship and participation rates report, October 2018. https://ncaaorg.s3.amazonaws.com/research/sportpart/Oct2018RES_2017-18SportsSponsorshipParticipationRatesReport.pdf
- Bassett AJ, Ahlmen A, Rosendorf JM, et al. The Biology of Sex and Sport. JBJS reviews. 2020;8(3):e0140.
- Covassin T, Elbin RJ, Harris W, et al. The role of age and sex in symptoms, neurocognitive performance, and postural stability in athletes after concussion. Am J Sports Med. 2012;40(6):1303-1312.
- Merrill A, Guzman K, Miller SL. Gender differences in glenoid anatomy: an anatomic study. Surg Radiol Anat. 2009;31(3):183-189.
- Flaxman TE, Smith AJ, Benoit DL. Sex-related differences in neuromuscular control: implications for injury mechanisms or healthy stabilisation strategies? J Orthop Res. 2014;32(2):310-317.
- Dragoo JL, Castillo TN, Braun HJ, et al. Prospective correlation between serum relaxin concentration and anterior cruciate ligament tears among elite collegiate female athletes. Am J Sports Med. 2011;39(10):2175-2180.
- Wolf JM, Cannada L, Van Heest AE, et al. Male and female differences in musculoskeletal disease. J Am Acad Orthop Surg. 2015;23(6):339-347.
- Doherty C, Delahunt E, Caulfield B, et al. The incidence and prevalence of ankle sprain injury: a systematic review and meta-analysis of prospective epidemiological studies. Sports Med. 2014;44(1):123-140.
- Hilibrand MJ, Hammoud S, Bishop M, et al. Common injuries and ailments of the female athlete; pathophysiology, treatment and prevention. Phys Sports Med. 2015;43(4):403-411.