Injuries in female athletes

During the last year, public interest in female professional football in Germany has risen, partly due to the success of the German women’s national team during the European Championship.
In the field of sports medicine, the focus is particularly on research into the causes and prevention of injuries to female athletes.

Injuries

In football, injuries to the lower limbs, especially to the ankle and knee joints, but also to the muscles, are among the main reasons for absence from training or competition [1]. Since, in addition to the initial event, secondary injuries at the same or at a different site during convalescence also play a signi­ficant role, targeted rehabilitation is of great importance, in addition to injury prevention. While in comparison between the sexes, men are more prone to lesions of the hamstrings and in the groin area, women are more likely to suffer injuries to the quadriceps or severe knee and ankle ligament injuries [2]. For this reason, prevention strategies should be tailored to the needs of female athletes.

Male-female differences

General considerations: Research into the biological diffe­rences between the sexes has increased significantly in recent years, and further findings relevant to prevention and rehabilitation are to be expected. Nevertheless, it is still the case that the majority of conclusions on optimising the aforementioned topics in professional football are based on studies predominantly involving male athletes [3, 4]. Differences exist, for instance, with regard to height, weight, muscle mass, and muscle fibre type and composition. In addition, there are also differences in maximum aerobic capacity (approx. 10 %) and in hormone household, whereby the 10 to 20 times lower testosterone levels are the main reason for the lower strength potential of women as compared with men [5].

Specifically the knee joint: Depending on the particular study, the risk of a cruciate ligament injury for women as opposed to men is about three to six times greater, especially regarding non-contact injuries. There are known anatomical and functional conditions, such as more cases of genua valga, excessive hip adduction and thus an increased Q-angle, quadriceps dominance with lower hamstring activity, increased tibial slope, narrow notch width as well as reduced trunk stability and increased femoral anteversion with the resulting internal rotation gait pattern. When comparing the sexes, this all results in creating an increased strain on the anterior cruciate ligament in female athletes. A temporal correlation of ligament injuries in female athletes, especially of the anterior cruciate ligament, can be found in the first phase of the menstrual cycle. The reasons for this range from the negative preovulatory effect of oestrogen on the tensile strength of the cruciate ligament up to a greater anterior laxity during the follicular phase. A clear additional hormonal effect on neuromuscular control has not been found [6, 7]. Whether the general risk of anterior cruciate ligament injury can be reduced by oral contraceptives does not appear to have been fully clarified [8].

Search for causes

We believe that the gender-specific differences in injury patterns can be attributed to both obvious and non-obvious causes (particularly at a professional or semi-professional level). Apart from the anatomical differences already mentio­ned, hormonal differences are of parti­cular relevance. And this is precisely where the problems of finding the causes arise in practice. The menstrual cycle appears to be a common exclusion criterion for involving female athletes in trials. Menstrual cycle-dependent changes are seen as a confoun­ding factor and, if at all, the athletes are therefore tested in isolated phases of their cycle in order to minimise their impact [9 – 11]. We regard the different financial circumstances in male and female football as a non-obvious cause. Whereas the men’s teams in the football Bundes­liga are made up exclusively of professionals, players in the women’s Bundes­liga often have a job or study commit­ments in addition. The whole focus, therefore, cannot be placed on prevention or, in the case of injuries, on rehabilitation. Experts believe that the conditions in terms of general training intensity and quality and the necessary medical and sports psychology support at a completely professional level exist in very few clubs in the first and second Women’s Bundesliga. Support with regard to athletic training or nutrition is also not comparable. It is noticeable, for example, that the frequency of injuries during matches is six to seven times higher than in training. It is therefore debatable whether training optimally prepares the players for the physical demands of the game, particularly with regard to non-contact injuries [1].

Prevention

General considerations: The current lack of data, coupled with the multifactorial causes of injury in female athletes, makes it difficult to develop an improved prevention strategy. Given that the anatomical differences cannot be changed, it is still possible to intervene in indivi­dual components of the causes of injury. In recent years, the German Football Association (DFB) has launched so-called “Performance Days” in coope­ration with the University of Freiburg. In addition to medical tests, bio­-mechani­cal examinations are also carried out at regular intervals on the selected female teams and special know­ledge is passed on to the players in the form of appropriate modules. The ultimate aim is to make the players more sensitive to topics such as injury prevention and performance optimisation, on the one hand, and to use the data obtained to generate assistance in working through movement-specific and muscle-stabili­sing deficits and to raise awareness of typical movements and injury situations. However, this indivi­dual approach involves a corresponding financial outlay, which is not usually available to aspiring professional female football players. The further dissemination of established prevention programs such as FIFA11+ [12, 13] or eccentric strength training (the Nordic hamstring exercise) [14, 15] could lead to a further reduction in injuries, including those to the anterior cruciate ligament. These measures and focus would seem recommendable in view of the current lack of professiona­lism in junior women’s football and the absence of support in the field of athletics. Contrary to expectations, their use in professional football is also currently low [16].

INFO: FIFA 11+ is a standardised warm-­up programme for the prevention of injuries to football players. It involves running exercises and other exercises for strength, plyometrics and balance.

Menstrual Cycle

Any general prevention strategy based on cycle-related performance and susceptibility to injury cannot be derived from current data [17]. Different performance-related parameters are affected during the menstrual cycle, but a direct impact of these parameters, and thus significant conclusions regarding recommendations and training individu­a­­li­sation, cannot be drawn with any certainty [18]. Based on self-reports from 1,086 female athletes from 57 types of sports, it was shown that cycle-related complaints, in particular dysmenorrhea and premenstrual symptoms, are widespread. The use of oral contraceptives appears to at least alleviate these symptoms. Only in rare cases are these symptoms taken into account when planning training and competition workload [19]. Different perceptions in relation to athletic workload differ during the indivi­dual menstrual phases.

The individual phases of the female cycle did not have an impact on the experienced level of exertion. Motivation and competitiveness, on the other hand, were assessed as better in the late follicular to ovulation phase. Mood disorders tended to occur prior to menstruation, while menstrual symptoms and a decrease in vigour were directly associated with menstruation [20]. The hormonal profile of the menstrual cycle varies both between individual athletes and between the individual cycles of one person. This poses a major problem when it comes to generalising training and prevention recommendations. The current findings are inconsistent and at times contradictory. However, there is general agreement that training and competition management should be adapted to take account of individual reactions to phy­sical performance during the different phases of the menstrual cycle [17]. Given the assumption that match performance is not significantly affected by the menstrual cycle phases [21], it seems difficult to achieve acceptance from all participants of the concept of individualisation, especially in team sports with several players and a full-time schedule. The personalised training plan, tailored to the phases of the menstrual cycle, is much easier to implement for the individual athlete. Ultimately, recording female athletes‘ symptoms during the menstrual cycle could be useful to raise awareness of the players involved of the physical and psychological aspects of the menstrual cycle and how it affects performance.

Conclusion

Changing prevention strategies to avoid injuries while taking the needs of female athletes into account would be desirable. Causes such as anatomical and physiological gender differences can only be influenced to a limited extent, if at all. The insufficient number of isolated studies available on female athletes is problematic. Causes and prevention strategies for injuries related to the female menstrual cycle cannot be clearly and broadly identified based on the data currently available.

References

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Autoren

Dr. med. Tobias Schmenn

ist Facharzt für Orthopädie und Unfallchirurgie mit Zusatzbezeichnung Sportmedizin. Er ist Oberarzt an der Sportklinik Hellersen sowie Teil des Teams im Prâvent Centrum Dortmund. Als Mannschaftsarzt betreut er die Frauen-Nationalmannschaft des DFB.

Carsten Lueg

ist Facharzt für Orthopädie mit Zusatzbezeichnungen Sportmedizin, Manuelle Medizin, Akupunktur, Gesundheitsförderung und Prävention. Er ist seit 2013 Gesellschafter des Prâvent-Centrums in Dortmund. Darüber hinaus ist er seit 2010 Mannschaftsarzt der FrauenNationalmannschaft des DFB.