Porter & Schon: Baxter's The Foot and Ankle in Sport, 2nd ed.
Section 4 - Unique Problems in Sport and Dance
Chapter 24 - Unique considerations for foot and ankle injuries in the female athlete
The passage of Title IX * is arguably the most important event in the timeline of women's participation in U.S. athletic endeavors. By almost any measure, the numbers of female athletes have exploded in multiple sports in the decades since 1972. Before Title IX, approximately 1 in 27 girls participated in sports; that number is now nearly 1 in 3. The National Collegiate Athletic Association (NCAA) tracks women's sports participation in its member institutions; the data are self-reported and are useful for evaluating general trends. In 1981, total athletes numbered 74,239. By 1993, the total had risen to 105,532 and then in 2001 to 155,513 ( Fig. 24-1 ). In general, the increase in participation reflects the addition of women's teams to institutions. The increase also reflects the elevation of previously emerging sports such as ice hockey and water polo to normal status and championship competition. Additional emerging sports, such as synchronized swimming, archery, badminton, equestrian events, squash, and team handball also have increased the numbers of athletes reported.
The increase in the number of women participating in sports and the increase in their level of competition has provided a new opportunity to study the effects of different sports on the athlete. Some sports provide the opportunity to directly compare injury rates for both genders. Other sports are the exclusive domain of the female athlete. There is great interest in identifying preventable injuries, whether they are sport specific or gender specific. The sports identified as causing the highest number of injuries in the female athlete are basketball, volleyball, field hockey, and gymnastics. Sports engendering the fewest injuries are golf, swimming, squash, and archery.        Additional information also has been garnered by the study of female military recruits and their physical performance compared with male peers. Military studies are intriguing because the male and female populations are subjected to the same conditions of training and physical standards.
Their data reveal significant and more rapid improvement in performance over sequential years for women compared with men. The higher injury rates initially reported in women have gradually begun to decline as women have adapted to the rigorous schedule. Physiologic differences, particularly in upper body strength in women, may be permanently limiting, although women appear to have comparable or better aerobic capacity. Other preliminary studies seemed to indicate a significantly higher rate of injury in the female athlete; however, follow-up studies demonstrated the injury rate to be sport specific. In these studies, proper conditioning resulted in injury rates equivalent to male athletes.
Anthropometric studies provide interesting data concerning anatomic differences between women and men. In women, lower extremities constitute 51% of their total height, compared with 56% in men. This difference improves the mechanical advantage for men in activities requiring striking, hitting, or kicking because of the greater force than can be generated by their legs as longer levers. The female has a wider pelvis, greater varus of the hips, and greater genu valgus than the male. As a result, females have a lower center of gravity, and in sports requiring excellent balance, such as gymnastics, females have a distinct advantage. As a result, the balance beam is a required element in competition for female gymnasts and is not included in the competition for male gymnasts. Female gymnasts typically also have better joint mobility, improving their flexibility—another trait valued in gymnastics. The alignment differences at the hip and knee may be one factor, along with the level of conditioning, contributing to higher percentages of overuse syndromes in the lower extremity in female athletes.
The musculoskeletal system in women contains less muscle mass and more fat for the same body weight than in men. In males and females with equal training, female muscle mass is approximately 23% of body weight, compared with 40% in males. This limitation of muscle mass handicaps females in their attempts to increase their power and speed. The larger percentage of fat, however, is an advantage in distance swimming events because of the improvement in insulation and buoyancy for the female swimmer. For instance, the speed record for swimming the English Channel is held by Penny Dean. Her one-way time in 1978 was 7 hours, 40 minutes.
It is important to preface any remarks on the female athlete with the gender-specific clinical diagnosis of the female athlete triad. The diagnosis refers to the interrelated problems of disordered eating, amenorrhea, and osteoporosis. Specific to the foot, these athletes are more at risk for stress fractures in the foot; and, in this instance, consideration of the diagnosis should be entertained and appropriate history sought. Any impression of osteopenia on plain x-ray, coupled with a history of amenorrhea and evasiveness about eating habits, should prompt further investigation. Failure to make the appropriate diagnosis can allow repetitive injuries to occur, possibly with significant changes in the normal bony architecture of the foot. The incidence of the disorder in young girls has been reported to be as low as 15% and as high as 65%. The prevalence may be higher in sports that select for a slim body habitus, but it has been reported in all sports.
When approaching the study of foot and ankle problems in female athletes, disorders can be divided into gender-specific disorders and sport-specific disorders.
* “No person in the United States shall, on the basis of sex, be excluded from participation in, or denied the benefits of, or be subjected to discrimination under any educational program or activity receiving federal assistance.”—Title IX of the Education Amendments of 1972 to the Civil Rights Act of 1964.
Ballet (Also See Chapter 21 )
The female classical ballet dancer is unique in her requirements for the lower extremities.   The dancer uses either a thin-soled slipper or toe shoe. The dancer typically will participate in several classes, rehearsal for performances, and then the performance or performances. The lower extremities are called on to absorb all the force of landings on the wooden dance floor. The consequence of the schedule of training and performance and the type of shoe for the foot leads to chronic injuries such as tendinitis, tendinosis, and impingement syndromes. The most common acute injury is the inversion sprain, usually occurring on landing a jump. Fatigue, improper technique, and anatomic variation from optimal body type all can be factors in acute and chronic injuries. The lower leg, foot, and ankle make up approximately 40% of dance injuries in a sport in which the lifetime incidence of injury is 90%.
Posterior Ankle Pain (Also See Chapter 2 )
Ballet requires extreme plantarflexion of the foot for en pointe work. In this extreme position, soft tissues posterior to the ankle can be compressed and irritated. Any one of the following structures posterior to the ankle can cause symptoms: an os trigonum, a large posterior process of the talus, or a large dorsal process of the calcaneus. Symptomatic flexor hallucis longus (FHL) tendinitis can be caused by these impingement scenarios. Diagnosis of this suspected condition can be supported by local tenderness proximal to the sustentaculum tali and pain with resisted plantarflexion of the great toe. Magnetic resonance imaging (MRI) typically will demonstrate fluid within the sheath of the tendon and sometimes marked tenosynovitis. Preservation of the function of the FHL tendon is paramount in dancers. Treatment should be aimed toward minimizing the inflammatory condition, with surgical intervention timed to allow appropriate recovery. In some instances, simple release of the FHL is adequate; in other cases, excision of the os trigonum or posterior process of the talus may be required. FHL tendon symptoms are most commonly associated with ballet; however, participants in other sports such as soccer increasingly are demonstrating the same entity.
Nearly half of reported dance injuries are categorized as acute. The most common injuries occur as the dancer lands with a loss of balance. If the dancer lands in en pointe position, the ankle is more stable, causing a midfoot injury rather than the typical anterior talofibular ligament injury. Radiographs should be obtained in the dancer who cannot walk more than three steps (limping is acceptable) and in whom there is tenderness over important anatomic landmarks. Foot x-rays should be obtained if there is tenderness over the navicular bone or the base of the fifth metatarsal. If there is tenderness over either the fibula or the medial malleolus from the tip to 6cm proximal to the tip, ankle films should be obtained.  
The most commonly overlooked fractures include the talar dome (see Chapter 14 ), the lateral process of the talus (see Chapter 14 ), the os trigonum (see Chapter 14 ), the anterior process of the calcaneus, and the proximal fifth metatarsal. Younger dancers can be more difficult to evaluate, often requiring repetitive x-rays. A high index of suspicion should be maintained, especially in the face of soft-tissue swelling over the physes of ankle or foot bones.
As in other athletes, inversion injuries can cause damage to structures other than the anterior talofibular ligament. Syndesmosis tears, osteochondral lesions of the talus, and subluxation or longitudinal tears of the peroneal tendons all may occur. Dancers also are at risk for subluxation of the cuboid, either associated with an inversion injury to the ankle or from repetitive plantarflexion and dorsiflexion. In this clinical entity, the base of the fourth metatarsal becomes dorsally displaced and the fourth metatarsal head displaces in a plantar direction. Additionally, cuboid dysfunction can interfere with normal function of the peroneal tendons and must be considered in dancers with peroneal tendinitis. Treatment of this unusual condition requires reduction of the cuboid with a squeeze technique after the hindfoot is mobilized and the forefoot is adducted.
Midfoot injuries in the dancer present a significant treatment dilemma because of the prolonged healing time required for stability of the foot and the difficulty of restoring the mobility required for dancing. Midfoot injuries occur when the dancer lands in full pointe, with the posterior lip of the tibia resting and locked on the calcaneus. In this position the subtalar joint also is locked, and the heel and forefoot both are in varus. Because the ankle joint is relatively stable in full pointe, the forces at landing are transferred to the midfoot. Treatment of these acute injuries requires evaluation of both stability of the involved tarsometatarsal joints and amount of collapse of the longitudinal arch (see Chapter 5 ). Some diastasis may be acceptable if weight-bearing views do not demonstrate collapse of the longitudinal arch. Workup should include weight-bearing views, comparison weight-bearing views, and computed tomography (CT) scan if necessary.
The fifth metatarsal is a common area of injury for dancers. The most innocuous fracture is that of avulsion of the base of the fifth metatarsal. Open reduction internal fixation (ORIF) is recommended only if the fracture fragment involves greater than 30% of the articular surface and is significantly displaced. The most typical fracture involves only the most proximal 1cm of the bone and usually is associated with an ankle sprain. It can be treated with appropriate immobilization and progressive activity as healing permits. The Jones fracture (see Chapter 4 ) occurs by the mechanism of adduction of the fifth metatarsal, usually while the foot is plantarflexed. Because of the negative effects of prolonged immobilization, early operative management for these fractures at the metaphyseal-diaphyseal junction is preferred.
Repetitive adduction forces that occur with cutting or pivoting movements can result in diaphyseal stress fractures. There usually are prodromal symptoms preceding an acute event. The history is critical, as is review of radiographs, which typically will demonstrate periosteal reaction, cortical thickening, intramedullary sclerosis, and widening of the fracture line. Because this is a vascular watershed zone, these stress fractures should be treated with intramedullary screw fixation, bone graft, or both.
When dancers perform the demi-pointe position, the foot is twisted and inverted and can incur an oblique or spiral fracture of the mid- to distal portion of the fifth metatarsal. This “dancer's fracture” now has been shown to heal well with conservative and symptomatic treatment rather than ORIF.
The female gymnast has been reported to be at higher risk for ankle injury than the male athlete. This is presumably because of the difference in alignment of the female lower extremity, with accentuated varus position of the heel. Landings on this varus position increase the probability of ankle sprain. Areas of complaint in the foot in female gymnasts include the bottom of the heel, the plantar fascia origin, and the medial longitudinal arch. Direct blows during landings or striking the heel on the floor while swinging under the lower uneven parallel bar cause pain under the heel. Tumbling is the typical cause of pain at the origin of the plantar fascia, whereas landings cause pain in the medial longitudinal arch or the forefoot. Interestingly, analysis of flexibility parameters in gymnasts compared with controls does not demonstrate a correlation to injury patterns or frequency. Ankle impingement syndrome (see Chapter 2 ) occurs in the female gymnast, with impingement occurring anteriorly when she lands short on her dismount, forcing her ankle into hyperflexion. If acute pain occurs with an instance of injury, the ankle should be rested and iced. Physical therapy modalities and anti-inflammatory drugs are also useful adjuncts. With return to the inciting activity, a large protective pad can be taped as a mechanical block along the anterior aspect of the ankle to help prevent reinjury.
Recreational Ice Hockey
There has been a phenomenal increase in the numbers of women participating in organized ice hockey within the last several decades. Estimated numbers in the United States and Canada increased by 250% in the latter 1990s; and because women's ice hockey was included in the 1998 Winter Olympic Games, participation is expected to continue to rise. Interest in injuries generated by the contact and collisions in ice hockey has led to many studies on male hockey players. The play rules are modified for women; intentional body checking is not allowed and the players are required to wear full-face protection (men wear one half). As a result, women suffer no dental or facial injuries, in sharp contrast to the high rate in men. When six male and six female collegiate teams were compared in a cohort study, the risk of severe injury (14 or more missed sessions) was 5.33 times higher for women than for men. The most common injuries in women were concussion, adductor strain, and ankle sprain. As the numbers of women participating in this sport increase, the data will clarify further the risk of injury to female athletes.   
Posterior Tibial Tendinitis (See Also Chapter 8 )
Hyperpronation of the foot in the female can cause either chronic posterior tibial tendinitis or insertional posterior tibial tendinitis. The previously discussed genu valgum in the female requires relatively more pronation in the foot to maintain the plantigrade position. Initial treatment for excessive pronation should include medial heel and forefoot wedge or posting within the athletic shoe, although benefit can be obtained with full-time use of mechanical correction in all shoes. Custom foot orthoses can be beneficial early in treatment. The insertional form of posterior tibial tendinitis can be more recalcitrant and difficult to treat. This disorder may be associated with the presence of an accessory navicular bone. In addition to foot orthotics, other treatments should include rest, ice massage, anti-inflammatory medications, stretching of the Achilles-gastrocnemius complex, and brace treatment with a short, articulated, ankle-foot orthosis or Arizona brace. In the very rare case, excision of the accessory navicular bone with repair or advancement of the posterior tibial tendon may be indicated. In some instances, this also will require supplementary tendon transfer.
Bunions (See Also Chapter 19 )
The incidence of bunions always has been reported as significantly higher in women versus men, with the implication that women's shoes have a slow deforming effect on the forefoot. The female athlete typically is well motivated to consider aggressive conservative treatment for bunions to remain active in her sport. Several aspects of bunions should be considered when evaluating potential causes of pain or dysfunction in the woman athlete with bunions. First, direct pressure from the shoe and especially from stitching lines on the shoe may cause soft-tissue irritation over the bunion. The structures most at risk for this type of irritation include the dorsal digital nerve and the capsular structures of the metatarsophalangeal joint. Second, the athlete may have suffered a capsular injury to the joint that will respond to rest or the use of a bunion night splint, combined with topical anti-inflammatory products. Women athletes with significant deformity may have first-metatarsocuneiform instability, which will respond well to treatment with an appropriately posted, custom, trilaminar foot orthosis. Because the risk of a significant change in the mechanical function of the foot can occur after bunionectomy, surgery should be avoided if possible. Postoperative changes in the foot can include residual stiffness in the metatarsophalangeal joint and imbalance in the forefoot load, potentially causing transfer metatarsalgia or stress fracture. Stress fractures of the base of the proximal phalanx of the great toe have been reported in athletes with hallux valgus.
Stress Fractures (See Also Chapters 3 and 4   )
Stress fractures occur as a result of repetitive, low-level stresses on bone and have multifactorial causes. In many athletic settings, women appear to be at higher risk for stress fracture than men.     In particular, a woman exhibiting the female athlete triad, previously mentioned, may be predisposed to stress fracture. If women with irregular menses are compared with women with regular menses, the frequency of stress fractures is increased by a factor of four. If all fractures are evaluated, the increase is three times the rate for athletes with regular menses. Some of the factors that have been identified as causative for stress fracture include dietary imbalance, foot structure, training surface, footwear, training variations, and temporary cessation of activity.
Lower bone density and potentially lower calcium intake compared with male athletes also may make the female athlete more susceptible to stress fracture. Menstrual irregularities such as exercise-induced amenorrhea may result in lower bone density. In particular, females who begin their running career before menarche may delay menarche because of excessive weight loss, low body fat, and subsequent loss of normal hormonal stimulation. High-level female runners demonstrate an incidence of menstrual irregularity of 50%. The use of oral contraceptives as an estrogen therapy can provide some protection by helping to maintain bone density.
Clinical symptoms of stress fracture can be insidious in onset, often interfering with the athlete's participation in the sport but not necessarily causing complete cessation of the inciting activity. Swelling may or may not be apparent, but there generally is point tenderness over the fracture. History of change in the training schedule or other causative factors may be difficult to obtain. Careful physical examination is paramount because any bone in the foot or the tibia and fibula can be fractured. Radiographs may be required sequentially because they are not always positive for the first 3 to 6 weeks. Bone scan is extremely valuable in making an earlier diagnosis in the athlete.
All medical support personnel involved in the care of the female athlete must keep several salient facts in mind. First, the number of females involved in all sports has increased dramatically and will continue to increase. Second, like their male peers, female athletes will continue to push their limits, likely incurring injury in the process. Third, injuries in the female athlete will fall into either sport-specific or gender-specific categories, the latter of which require a higher index of suspicion and perhaps greater depth of knowledge for diagnosis and treatment. This is a pivotal time for women's sports medicine, with great opportunity to gather data, to refine optimal treatment recommendations, and to develop strategies to prevent injury. This chapter delineates many of the injuries that the medical personnel will encounter and, we hope, has given the reader a better understanding of salient features of diagnosing and treating these injuries.
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