Injuries in Competitive Austrian Gymnasts

Background: Competitive gymnastics is a physically demanding sport that requires flexibility, coordination, endurance and strength. The biomechanics of the sport also result in a specific injury profile. Methods: A total of 30 gymnasts from the Austrian national team (21.9±3.9 years) and 25 competitive gymnasts not affiliated with the national team (22.8±6.4 years) provided information on their injuries of a 3-year period (2018-2020) via an online survey. The injury rate per 1000 hours of training was calculated and injuries were stratified by severity, injured body structure and the localization of the injury. Mann Whitney U and Chisquare tests were used to examine differences between national team and non-national team gymnasts. Results: A total of 64 injuries were reported, which resulted in 0.4 injuries per 1000 hours of training. There was no difference in injury rate per training hours; national team members, however, reported significantly more injuries per person compared to their non-national team peers (1.4±1.1 vs. 0.8±1.0; p=0,04). The most common tissue affected by injuries were tendons and ligaments (59%) while muscle injuries were the least common injuries (11%). Almost half of the injuries (47%) affected the lower extremities, with ankle injuries being the most common ones. Roughly 80% of injuries were considered minor to moderate and could be treated via outpatient care. Across the different disciplines of gymnastics most injuries were reported during floor routines (36%) followed by vault (16%). Conclusion: Injury risk was directly associated with training volume. Severe injuries, however, were rare even in highly competitive gymnasts.


I. INTRODUCTION
Gymnastics has its origins in Germany with Friedrich Ludwig Jahn (1778-1852) being considered the "father of gymnastics", as he was the most important pionier of gymnastics (Prohl, 2009). Competitive gymnastics of today, however, have very little in common with the original forms. Above all, the level of performance has undergone tremendous development over the past several decades. In order to be able to compete at the highest levels, gymnasts need to engage in a large volume of training at high intensities. This excessive training puts a considerable strain on the musculoskeletal system, which increases the risk for both acute and chronic injuries (Grim & Engelhardt, 2016;Boschert, 2016). Various studies have shown injury rates of 1.4 to 8.5 injuries per 1000 hours of training (Bak et al., 1994;Caine et al., 2003;Caine & Nassar, 2005;Desai et al., 2019;Harringe et al., 2007;Marshall et al., 2007). Nevertheless, compared to ball sports or martial arts, competitive gymnastics has a low risk of injury based on relative and absolute injury frequencies (Kirialanis et al. 2002;Zetaruk et al., 2005;Knobloch et al., 2006;Greier, 2012;Greier et al., 2013).
The pronounced increase in performance in competitive gymnastics is largely due to the actions of the World Gymnastics Federation (Fédération International de Gymnastique, FIG), which evaluates performance based on aesthetics and technical difficulty. The final score, therefore, is a combination of two parts, which evaluates execution (E-score) and difficulty (D-score) of the performed elements within a gymnastics routine. All elements in competitive gymnastics are graded according to difficulty in the socalled Code de Pointage and assigned a specific point value (Boschert, 2016;Fédération Internationale de Gymnastique, 2021a;Fédération Internationale de Gymnastique, 2021b). Competitive gymnastics has been part of the Olympic program since 1896 in men and 1928 in women. Some of the disciplines within gymnastics are specific to men or women. In women, the Olympic all-around competition consists of 4 disciplines (balance beam, uneven bars, floor and vault; Fig. 1).
The Olympic all-around event for male gymnasts consists of 6 disciplines (Keith, 2013) (high bar, parallel bars, floor, vault, rings and pommel horse; Fig. 2). In Austria there are about 450 gymnastics clubs with over 90,000 members. Nevertheless, competitive gymnastics has not been at the forefront in Austrian sports. As competitive gymnastics is a technically demanding sport, training must begin in early childhood (d 'Hemecourt & Luke, 2012). At the elite level gymnasts are classified by the framework of the Austrian national team squad, which has minimal sexspecific differences. Male gymnasts are separated into A and B squads with the A squad representing the highest performance level (ÖFT, 2021a). Female gymnasts within the national team, on the other hand, are separated into three categories (ÖFT, 2021b).
Most injuries in competitive gymnastics are the result of excessive active and passive impact forces during jumps and landings as well as strong tensile loads due to acceleration and centrifugal forces (Boschert, 2016). A recent meta-analysis, which included 22 studies from nine countries examined type, severity and progression of the injuries. The results indicated a higher injury risk in older and heavier gymnasts but also showed a direct association with the number of training hours and, accordingly, performance level (Campbell et al., 2019). Data on causes, type and frequency on injuries in Austrian gymnasts, however, remain limited. The purpose of this study, therefore, was to provide information on injuries that Austrian competitive gymnasts suffered over a three-year period (between 2018 and 2020).

A. Participant
In order to be included in the study, participants had to participate in competitive gymnastics for at least 3 years. Women needed to be at least 16 years of age while the minimum age for men was 18 years, as these are the minimum age requirements specified by FIG regulations. Participants were divided into national team members and competitive gymnasts that were not part of the national team (non-national team). The criteria for the national team group were membership of squad A or B for men and levels 1 or 2 for women. Non-national members needed to participate in the Austrian national championships in order to be eligible for participation.
In addition to age and gender, participants reported their average training time in hours/week. Further, participants provided information on injuries suffered in the context of gymnastics over a period of 36 months (between 2018 and 2020). In the present study injuries were defined as an acute physical damage sustained in the context of competitive gymnastics hat led to consultation with a physician. The cause of the injury and equipment were reported by gymnasts while the diagnosis was based on the physician's evaluation. Reported injuries were divided into three groups according to severity. Severity I required only a single medical treatment while severity II injuries required multiple outpatient medical treatments, and severity III injuries required inpatient treatment (Greier & Leimlehner, 2014).

B. Design
Information on injuries in active Austrian competitive gymnasts was obtained via an online survey that was distributed via staff and coaches of the Austrian professional association for gymnastics (österreichischer Fachverband für Turnen). The questionnaire has been validated previously in martial arts athletes (Greier et al., 2013).

C. Statistical Analyses
Interval scaled data are presented as means with standard deviation. The number of injuries per thousand trainings hours was calculated and Mann Whitney U-tests were used to examine differences between national team and non-national team gymnasts. In addition, chi-square tests were used to examine differences by injury type and the injured body structure. All statistical analyses were carried out with SPSS 26.0 (IBM, Armonk, NY) and statistical significance was set at p < 0.05.

III. RESULTS
A total of 55 competitive gymnasts completed the questionnaire, of which 30 were members of the national team (53.3% women) and 25 were non-national team gymnasts (44.0% women). Across the entire sample, participants were 22.4±3.8 years of age and engaged in an average training volume of 19.7±6.4 per week. There was no difference in age and years of participation in competitive gymnastics between national team and non-national team members. Training volume, however, was significantly higher in national team members (Table I). A total of 64 injuries were reported across the entire sample (Table II). The number of injuries reported by national team gymnasts was more than double the number of non-national team members (43 vs. 21) and 73% of national team gymnasts reported at least one injury that was attributable to gymnastics. In nonnational team members only 52% reported at least one injury that was attributable to gymnastics. The average injury rate per person was 1.2±1.1, with higher rates in national gymnasts (1.4±1.1) compared to non-national team gymnasts (0.8±1.0) (p = 0.04). Relative to training volume, no difference in injury rate, however, was observed between national team and non-national team gymnasts (0.4/1000 hours of training in both groups). There was also no significant sex-difference in injury rate per person (1.3±1.1 in women vs. 1.1±1.1 in men).
Most injuries (86%) occurred during training with injuries of tendons and ligaments being the most common ones in both groups. In fact, 33% of national team gymnasts and 21% of non-national team gymnasts reported at least one ankle injury during the 36 months observation period. Muscular injuries were the second most likely injury in national team gymnasts while these were not reported in non-national team gymnasts (Table II). Across the entire sample half of the injuries required only a single treatment. In national team gymnasts grade 2 injuries, which require multiple outpatient treatments were the second most common injuries while injuries requiring inpatient care were the second most common injuries in non-national team gymnasts www.  (Table III). Nevertheless, national team gymnasts displayed a higher prevalence of moderate to severe injuries (grade 2 and 3) compared to non-national team gymnasts (p < 0.05). The majority of injuries occurred at the lower (46.9%) and upper extremities (42.2%) (Fig. 3). The shoulder was the most commonly affected structure in upper extremity injuries (16%) and ankle injuries were the most common injuries in the lower extremities (25%). While ankle injuries were the most common injuries in both groups of gymnasts, shoulder injuries were more common in national team gymnasts compared to non-national team gymnasts (18.6% vs. 9.5%). Non-national team gymnasts, on the other hand, reported a higher prevalence of knee injuries. Injuries to the wrist were also more common in nonnational team athletes while the prevalence of injuries to the fingers was similar in both groups. Nearly every second injury occurred during a specific gymnastics element (45.2%), followed by landing actions (30.3%). Jumping, equipment collisions and falls each accounted for less than 10%. There were no significant differences between the performance classes in the cause of injuries.

IV. DISCUSSION
The present study examined the injury history of 55 Austrian competitive gymnasts over a three-year period via an online questionnaire. A total of 64 injuries were reported, which resulted in an exposure-time related injury rate of 0.4 injuries per 1000 hours of training. Most injuries (86%) occurred during training and affected tendons and ligaments (59.4%), with the ankle being the most commonly injured body part. Across gymnastics disciplines most injuries (36%) occurred during floor routines.
The injury rate in the present study was considerably lower compared to previous studies, which reported injury rates between 1.4 and 8.5 injuries per 1000 hours of training (Bak et al., 1994;Caine et al., 2003;Caine et al., 2005;Desai et al., 2019;Harringe et al., 2007;Marshall et al., 2007;Paxinos et al., 2019;Thomas & Thomas, 2019). Some studies also reported that more injuries occurred during competition (Marshall et al., 2007;Hart et al., 2018;Kruse et al., 2021) while others confirmed the results of the present study that more injuries occurred during training (Kolt & Kirkby, 1999;Heitkamp & Horstmann, 2005). The variability in the results across studies may be explained by differences in training volumes, performance levels and age of the study populations as well as inconsistent definitions of injuries. Compared to other sports such as ball games and martial arts, competitive gymnastics, nevertheless, has been shown to have a relatively low injury risk (Zetaruk et al., 2005;Kirialanis et al., 2003;Kirialanis et al., 2015). The injury risk in martial arts, for example, has been shown to be 3 times that of competitive gymnastics (Greier et al., 2013). Severe injuries are also less common in gymnastics (Kirialanis et al., 2002, Kirialanis et al., 2015, Greier & Leimlehner, 2014, Campbell et al., 2019. In the present study almost 80% of injuries required only outpatient care. The higher prevalence of moderate to severe injuries in national team gymnasts compared to their non-national team peers may be attributed to the greater technical difficulty and potentially higher external forces that the body is exposed to. The high prevalence of ankle injuries has been attributed to the large amount of landing and dismounting elements that are performed in gymnastics (Marshall et al., 2007;Thomas & Thomas, 2019;Hart et al., 2018;Seegmiller & McCaw). With landings and take-offs being common during floor routines it is also not surprising that floor exercises were associated with the highest injury risk even though they are performed on suspended floor constructions (Sands, 2005). Shoulder injuries were also common, particularly in national team gymnasts. The lower injury rate in non-national team gymnasts may again be attributed to the difficulty of the gymnastics elements performed and the external forces experienced. Particularly during routines on the rings and high bar high tensile loads can occur due to acceleration and centrifugal forces (Boschert, 2016;Caine & Nassar, 2005;Gerhardt et al., 2014). Injuries to the wrist, on the other hand, are attributed to high loads during supporting elements, which are performed at any level. Excessive loads due to high repetitions of such elements may also result in overuse injuries that are commonly referred to as "gymnast wrist" (Wolf et al., 2017).
Despite the relatively low injury risk of competitive gymnastics there remain continued efforts to reduce the injury risk by constantly trying to improve and develop safe gymnastics equipment. Elastic floors and mats with high shock absorption properties minimize ground reaction forces during landing elements. Further, foam pits are used to provide a safe space for learning new, more difficult gymnastics elements (Sands, 2005). Various studies also showed that injuries occur commonly during gymnastics elements that are already well mastered (Heitkamp & Horstmann, 2005;Kirialanis et al., 2003), which indicates to a lack of concentration during the exercise routine rather than lack of physical preparedness (Caine & Nassar, 2005). The training, therefore, should be variable in order to avoid undue central fatigue (Kolt & Kirkby, 1999).
Additionally, a comprehensive, age-and performance-specific training is a critical component in longterm injury prevention. Such a training should aim for the development and perfection of all sport-specific requirements and should facilitate a reliable mastery of gymnastics elements during competition (Schwabowski et al., 2010). Such a training further includes the systematic development of high stresstolerance of all components involved in the sport (Weineck, 2007). Besides physical conditioning and specific skill training, proprioceptive training exercises on balance disks that improve intra-muscular coordination have been successfully implemented to reduce ankle and knee injuries in other sports like volleyball (Verhagen et al., 2004). The implementation of such exercises could also be valuable in gymnastics. Finally, regular medical examinations by certified physicians are recommended. These examinatins should already take place when entering competitive gymnastics training and continue with annual check-ups, with a special focus on the musculoskeletal system (possibly including x-ray). This allows to identify developing or underlying existing problems early and provides the opportunity to take corrective actions.

A. Limitations and Strengths
Some limitations of the present study should be considered when evaluating the results. Data was collected via an online survey, which has an inherent risk of reporting bias. Given a 3-year observation window, it can also be difficult to remember all injuries, particularly if they were only minor. The long observation period along with stringent inclusion criteria, on the other, may also be a strength of the study as it may reflect the injury risk in general, rather than during specific training periods. Nevertheless, the small sample size and voluntary participation, may limit generalizability of the results. The low number of participants, however, may also be attributed to the low number of competitive gymnasts in Austria and the fact that details on the type and cause of injuries were collected should be considered a strength of the study.

V. CONCLUSION
Overall the results of this study indicate a relatively low injury risk of competitive gymnastics compared to other sports such as ball games and martial arts, particularly concerning severe injuries. Within the different disciplines of gymnastics most injuries occurred during floor routines followed by vault. Tendons and ligaments were the most affected body structures and the ankle was the most affected body part. There was also a direct association between training volume and injury risk. Training loads, therefore, need to be carefully monitored to minimize the injury risk. The increasing difficulty of gymnastics elements further warrants continued efforts regarding the development and improvement of gymnastics equipment to minimize the injury risk in competitive gymnastics.