Despite tremendous growth in participation, the injury rate and injury profile in women's collegiate soccer players have remained relatively stable over the past 15 years, with a nonsignificant increase in game injury rates and a nonsignificant decrease in practice injury rates over the sample period. Although it would be difficult to confirm, we speculate that the recent emphasis on preventive strategies and programs that include flexibility, plyometric, strength, and neuromuscular training specifically designed for reducing ACL injuries and ankle sprains may have contributed to the fact that injury rates have not risen, despite an increase in the intensity of competition over the 15-year period. The game injury rate was just over 3 times higher than that observed during practice, and this relationship has also remained stable over time. This relationship is also consistent with recent reports of adolescent soccer players indicating a predominance of lower extremity injuries that are, for the most part, minor.
For a variety of reasons, however, caution should be used when comparing this current NCAA ISS data with previous descriptive injury studies. Often the injury definitions and methods were different among studies. Several authors did not use a time-loss definition for injury, and many did not incorporate A-Es as the denominator. Furthermore, data collection for previous studies was not performed by certified athletic trainers, and the data entry intervals were not consistent with those used in this current NCAA ISS report. The NCAA ISS system is unique in that it relies on certified athletic trainers to collect data, and data entry occurs in a timely fashion, as opposed to investigations by other researchers, who may have relied upon nonmedical personnel for providing data such as that included in insurance claims or coaches' reports.
Despite these limitations of previous studies, the current injury distribution is similar to that reported at other levels of soccer play, demonstrating that more than two thirds of all injuries occurred in the lower extremities. Ankle sprains were the most common game injury, and knee internal derangements resulted in the greatest time loss,
as demonstrated in both outdoor and indoor soccer games
and at all levels of competition.
For games, the regular-season injury rate was significantly higher than that for the postseason, whereas for practices, the preseason injury rate was significantly higher than that for the regular season or postseason. Some speculate that increased ability is associated with a higher incidence of injury, but these current results indicate no difference, at least in practice injury rates, among Divisions I through III. Furthermore, the assumption that Division I athletes are more skilled than those in Divisions II or III has not been established.
The most common injuries in games were ankle ligament sprains, knee internal derangements, and concussions. These results are not surprising and underscore the need for prevention of lower extremity injuries and concussions. Soccer players are often resistant to using ankle braces or to having their ankles taped for activity, but the high incidence of ankle ligament sprains emphasizes the importance of preventive programs to identify athletes with injuries that may not have been properly rehabilitated or for whom taping or bracing might be appropriate. These programs have been successful in decreasing injuries in soccer players.
For practices, the most common injuries were upper leg muscle-tendon strains, ankle ligament sprains, and knee internal derangements, again underscoring the need for future research to determine methods to prevent these injuries. Concussions and other facial injuries did not occur commonly in practices.
These data also highlight the frequency and effect of knee ligament injuries in female soccer players. These injuries remained mostly noncontact in both practices and games. This game ACL injury mechanism is consistent with that recently reported by Fauno and Wulff Jakobsen,
who noted that for 113 confirmed ACL game injuries, the mechanism was predominantly noncontact.
The prominence of ACL injuries in women's sports has driven research initiatives aimed at identifying risk factors, which could help us to develop preventive measures.
In 1999, Hewett et al
provided neuromuscular training to soccer, basketball, and volleyball players for sessions of 60 to 90 minutes, administered 3 times per week for 6 weeks, and demonstrated a 72% decrease in noncontact ACL injuries. This type of injury risk information has led many NCAA schools to incorporate preventive neuromuscular control exercises and agility tasks during practices and conditioning. These programs all have strength, flexibility, agility, aerobic conditioning, plyometrics, and risk awareness training in common.
Preliminary reports do support the effectiveness of such neuromuscular training programs in preventing ACL injury.
Mandelbaum et al
demonstrated that in 14-year-old to 18-year-old soccer players, an intervention program (Prevent Injury and Enhance Performance Program) emphasizing proprioception and neuromuscular training was associated with a 74% reduction in ACL tears over the subsequent 2 years. The intervention program included 20 minutes of soccer-specific agility drills, plyometrics, lower extremity and trunk stretching, strengthening exercises, and general warm-up activities. However, additional research using randomized, controlled designs is necessary to evaluate the effectiveness of these types of programs in reducing the rate of ACL injuries in female collegiate athletes.
Although knee internal derangement injuries resulted in the greatest time loss per incident, ankle ligament sprains remained the most common injury seen in practices and games. Ankle ligament sprains are typically considered less severe than knee internal derangements, but they accounted for a considerable portion of time-loss injuries. Significant research has focused on the effectiveness of preseason screening for ankle laxity and/or inadequate rehabilitation from prior ankle injuries in preventing future ankle sprains in soccer.
Unfortunately, many of these injuries are recurrent and occur even when protective strapping is in place.
Neuromuscular training strategies, however, do offer promise in reducing ankle injury and reinjury. McGuine and Keene
found that a combined preseason and in-season balance training program significantly reduced the rates of both first-time and recurrent ankle sprains. Given the frequency and severity of ankle injuries in women's collegiate soccer players, athletic trainers should focus on the implementation and the effect of preventive measures in limiting the occurrence and recurrence of ankle sprains.
Concussions are another frequent and important injury in collegiate female soccer players, accounting for 8.6% of game injuries overall and 6.0% of game injuries resulting in more than 10 days of time loss. The primary mechanism of head injury in this study, player contact, was also identified as such by previous authors investigating collegiate soccer.
Fuller et al
studied videotapes of international men's and women's soccer games (19
802 player-hours of match-exposures) and evaluated the mechanisms of head and neck injuries. Concussions accounted for 11% of the injuries, and the most common mechanisms involved (sometimes overlapping) challenges while both athletes were in the air (55%) and the use of the upper extremity (33%) or the head (30%). Of all player actions, unfair use of the upper extremity was most commonly associated with injury. Similarly, Anderson et al
reported that heading duels accounted for 58% of head injuries, with upper extremity contact accounting for 41% and contact with the opponent's head accounting for 32% (again, the types of contact can overlap). Although player-to-player contact has been consistently identified as a head injury mechanism, contact with the ball has not. Fuller et al
found that only 1 cervical strain of 248 head and neck injuries could be attributed to purposeful heading of the ball. Anderson et al
did not identify heading the ball as a mechanism for head injury. These results support those of previous researchers, who have failed to identify purposeful heading as a primary cause of concussion.
Specific circumstances and player actions have been recognized as risk factors. The risk of injury is considered to be highest in the first and last 15 minutes of play, when players are fighting for possession of the ball in the attacking and defending areas close to the goal.
Players are at an increased risk for injury when they receive or deliver a tackle or charge and when they are involved in play that is unfair or illegal.
Anderson et al
reported that 20% of head injuries due to elbow-to-head contact were related to illegal, purposeful use of the upper extremity during an aerial heading challenge. Fauno and Wulff Jakobsen
noted that 11% of ACL injuries were associated with the administration of a red or yellow card to the opponent. Therefore, as in other contact and collision sports, proper enforcement of the rules by officials is likely important in decreasing the risk for injury.
Player contact appeared to account for the majority of game injuries, whereas injuries from noncontact mechanisms (no direct contact to the injured body part) were predominant in practices. This may be because overuse injuries are more likely to be reported by players during practices and less likely to be reported during games.
Muscle-tendon strain injuries are common in soccer because of the nature of the sport, which involves running, sprinting, and sport-specific skills that often require the player to kick or strike the ball with full force. Strains involving the lower extremity predominate, again because of the acceleration and deceleration forces required during running and cutting and the overuse of these muscles with soccer-specific play. Many of these muscle strains can be addressed with better stretching and other injury prevention measures.
Given the contact nature of soccer, contusions are also common, frequently involving the lower extremity. Large muscle contusions involving the quadriceps are typical.
For both games and practices, fractures are relatively uncommon in women's soccer players. When they do occur, they are more likely during games and are also more likely to affect the upper extremity. The mechanism of these injuries, although not reported, is most likely due to falling on an outstretched hand (hand, wrist, and finger injuries) or landing on the shoulder (clavicle fracture). Lower leg fractures are uncommon and most often occur as a result of trauma to the lower leg. Shin guards may be useful in protecting against lower leg injuries and fractures.
Prior injury has also been associated with an increased risk of injury.
This factor emphasizes the need to evaluate athletes before the competitive season to identify those at risk based on a previous injury history, specifically focusing on injuries that have not been effectively rehabilitated. Hagglund et al
found a 2-fold to 3-fold increase in injury in soccer players with a history of hamstring strain, groin injury, or knee joint trauma, with the injury occurring in the previously injured site. Injury prevention strategies specific to hamstring injuries,
and ACL injuries
are all promising areas of further research. Inadequate rehabilitation and preexisting ligamentous laxity from prior injuries are thought to be risk factors for knee and ankle injuries,
underscoring the importance of detecting these problems in preseason evaluations. Athletic trainers can play a significant role in screening for injury history, preexisting injuries, and injuries that have not been appropriately rehabilitated.
In summary, most of the injuries in women's soccer affected the lower extremities, with ankle ligament sprains and knee internal derangements representing the most common game injuries. Furthermore, concussions continue to be a concern during games. Despite increased focus and research addressing knee internal derangements and concussions in women's sports, evidence to indicate that preventive measures have reduced the risk of these injuries is limited. The lack of a significant upswing in injury rates over the past few years, despite the escalating intensity of competition, may reflect the benefits of injury prevention strategies. However, additional research is needed to evaluate mechanisms of concussion and knee injuries and the preventive effect of current programs, such as those emphasizing neuromuscular control or cognitive testing, on injury prevention.