Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 201 Science of Gymnastics Journal THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS COMPARED TO YOUNG ATHLETES - PILOT STUDY Dávid Líška, Juraj Kremnický Faculty of Arts, Department of Physical Education and Sports, Matej Bel University, Banska Bystrica, Slovakia Original article DOI:10.52165/sgj.14.2.201-210 Abstract Gymnastic training develops strength, flexibility, concentration, balance, precision, and speed. The purpose of the study is to determine if gymnastic preparation leads to an increase in weight- bearing ankle dorsiflexion range of motion in a closed kinematic chain in young artistic gymnasts compared to a different type of sport. The weight-bearing lunge was chosen to measure the dorsiflexion range of motion in the ankle joint in the closed kinematic chain. The first group consists of members of the Slovak national youth team in artistic gymnastics (n-26). The second group consists of members of the Slovak national team in rhythmic gymnastics (n- 13). The control group consists of young athletes (n-22). The mean dorsiflexion range of motion in artistic gymnasts was 47.32 ° in the right ankle joint and 44.75 ° in the left ankle joint. The mean dorsiflexion range of motion in rhythmic gymnasts was 44.32 ° in the right ankle joint and 43.41 ° in the left ankle joint. The mean dorsiflexion range of motion in young athletes was 44.27 ° in the right ankle joint and 42.32 ° in the left ankle joint. Results indicate a statistically significant difference in favor of artistic gymnasts compared to rhythmic gymnasts at the right ankle joint (p-0.04). In the left ankle, the two groups did not differ significantly from each other (p-0.38). There was no significant difference between artistic gymnasts and athletes in the right ankle joint (p-0.09) and the left ankle joint (p-0.19). There was no significant difference between rhythmic gymnasts and athletes at the right ankle joint (p-0.38) and the left ankle joint (p-0.24). A greater dorsiflexion range of motion in a closed kinematic chain in the ankle joint was detected in young gymnasts compared to rhythmic gymnasts. There was no significant difference between artistic gymnasts and athletes. Keywords: weight-bearing lunge test, range of motion, artistic, rhythmic gymnasts, athletics. INTRODUCTION Gymnastics requires a high level of ability of motor control and a combination of several attributes to achieve optimal performance (Marcolin et al., 2019; Nassib et al., 2020). Gymnastics is a complex sport. Gymnastics can be divided into sports, modern, acrobatic, rhythmic, and aerobic gymnastics. Other gymnastic disciplines include tumbling and trampoline jumping. In artistic gymnastics, men have six apparatuses - floor exercise, pommel horse, rings, vault, parallel bars, and horizontal bar - on which they showcase their skills. Women compete on four apparatuses - vault, uneven bars, balance beam, and floor exercise. Modern rhythmic gymnastics is one of the few purely women's sports. Its main characteristic is the inclusion of equipment in exercises: skipping rope, hoop, ball, cones, and ribbon. Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 202 Science of Gymnastics Journal Gymnastics is a type of sport that requires a high level of anaerobic activity to achieve optimal results. Additionally, gymnastics enhances the development of abilities such as explosive strength, balance, coordination, and agility. The gymnast controls numerous basic elements to adapt to a higher load. Gymnastics also requires a high level of neuromuscular control (Kochanowicz et al., 2018). Repetition of difficult elements in training leads to skeletal adaptations (Knorr, 2014). The human body is adaptable due to its ability to react to repetitive loading. The human locomotor system is especially sensitive to adaptive changes during the adolescence period. Adaptation of range of motions in various joints is one of the adaptive factors for young gymnasts. Both decreasing or increasing the range of motion increases the risk of injury to gymnasts. Prevention of injuries in gymnastics is a great challenge (Kerr, 1990). In gymnastics, acute and chronic injuries can occur (Desai et al., 2019; Kolar et al., 2013). The most common cause of chronic injuries in gymnastics is overloading or inadequate treatment of acute injuries (Bradshaw & Hume, 2012; De Carli et al., 2012). The biomechanics of gymnastic exercises leads to the unique involvement of the body in different positions. These positions often require an excessive range of motion in various joints. It can lead to a higher incidence of hypermobility in gymnasts and predisposition to injury. Higher incidence of generalized joint hypermobility may result in musculoskeletal injuries in many sports activities (Schmidt et al., 2017). In addition to generalized hypermobility, localized hypermobility increases the risk of injury (Antonio & Magalhaes, 2018). In general, there is a higher incidence of hypermobility in gymnastics compared to other sports. One of the most common injuries in this sport is ankle joint injury (Edouard et al., 2018; Hart et al., 2018). There are several testing possibilities to measure the range of motion of the ankle joint. Measurement using a weight-bearing lunge test in a closed kinematic chain is potentially one of them. This pilot study aims to determine the weight bearing ankle dorsiflexion range of motion in a closed kinematic chain in young artistic gymnasts compared to athletes engaging in different sports, and to determine whether gymnastic training causes hypermobility in the ankle joint. METHODS Three groups of athletes participated in the study – young artistic gymnasts, rhythmic gymnasts, and young athletes. Young athletes included in the study train for a minimum of two years in a certain sport and only in one discipline. Athletes who train in more than one sport discipline and athletes with acute lower limb injury or infectious disease were not included in the study. Gymnasts were tested in January 2021, during a gymnastic team camp in X- Bionic Sphere in Šamorín. The athlete testing took place in Banská Bystrica. Testing was conducted before training so that training did not affect the range of motion in the ankle joint. The informed consent was signed by the parents. The first group consisted of 26 members of the Slovak national youth team in artistic gymnastics. Of these, 13 gymnasts were female and 13 gymnasts were male. The mean age was 14.28 years (±2.90). The mean weight was 47kg (±2.90). The mean height was 156.65 cm (±10.12). The mean training time was 9.34 years (±3.16). The median training time was 9 years. The second group consisted of 13 female members of the Slovak national team in rhythmic gymnastics. The mean age was 14.84 years (±1.20). The mean weight was 48kg (±7.4). The mean height 162 cm (±4.4). The mean training time was 11 years (±1.8). The median training time was 11 years. The third group consisted of 22 members of an athletic training group for children. Of these, 10 athletes were female Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 203 Science of Gymnastics Journal and 12 athletes were male. The mean age was 13.54 years (±1.4). The mean weight was 47,14kg (±7.79). The mean height was 160, 7 cm (±9.55). The mean training time was 4.36 years (±1.68). The median training time was 4.5 years. Artistic gymnastics training Sports preparation in artistic gymnastics consists of physical activity focused on the development of physical abilities and aesthetic awareness. In competition, athletes perform their routines with standardized apparatuses. Evaluation of every routine reflects its difficulty and execution value according to the current Code of Points. Talent identification and selection in gymnastics occurs in children aged 4 to 5 years. At the age of 11 to 14 years, athletes already train 5 times a week; the mean time per training unit is 180 min. Training focuses mainly on mastering flawless techniques for difficult elements. It must consist of a comprehensive development of physical abilities and increasing the difficulty of routines in every discipline. The best gymnasts participate in international competitions. Typically, they participate in 6 to 10 competitions a year. Rhythmic gymnastics training Rhythmic gymnastics is coordination – aesthetic sport. It combines ballet, dance, and acrobatics with expressive movement and manipulation of hand apparatuses. Performance in rhythmic gymnastics consists of mostly noncyclic movements demanding a high level of neuromuscular coordination. Gymnasts perform a variety of body movements, often using a maximum range of motion with music and according to the current Code of Points. Training consists of developing a technique of floor (freehand) exercises such as leaps, balances, pivots, and flexibility movements along with techniques of manipulating the hand apparatuses such as tossing, catching, and rolling. Rhythmic gymnasts begin with systematic training at a very young age, achieving maximum performance before 20. At preschool age, training focuses mainly on the comprehensive development of all physical abilities. For young gymnasts, it is necessary to gain control over coordination in connecting various body movements and basic skills. Young gymnasts train five times a week, 3–5 hours a day, focusing mainly on joint flexibility, especially the hip joint and spine. Young athletes training Many children at the age of 13 already have 4–8 years of systematic training behind them. The mean time of a training unit is 60 min, twice a week. Training consists of athletic exercises, gymnastic exercises, conditioning, and sports games (Čillík & Willweber, 2018). Children participate in athletic competitions several times a year. Preparation focuses on building a foundation for simple athletic disciplines – sprints, middle-distance running, relay running, long jump, high jump, and ball throw. Training is universal, varied, and conducted in a playful way. At the age of 12 to 13 s, athletes train 3 times a week, 60 to 90 minutes per training unit. Training focuses mainly on achieving the correct technique in basic athletic disciplines. Regional competitions take place 7 to 8 times a year. Training is still very comprehensive at both levels an focuses on the development of physical abilities and athletic disciplines. Weight-bearing lunge test. The weight-bearing lunge test focuses on measuring the dorsiflexion range of motion in the ankle joint in the closed kinematic chain. The test is conducted in a lunge position using a goniometer. The tested athlete performs lunge position with heel and hallux aligned. An attempt is not valid if knee valgus-varus occurs or if the heel lifts off the floor. The heel is in contact with the floor during the whole movement. The physician ensures that the ankle joint reaches maximum dorsiflexion in the lunge position. The other lower limb stays on the floor. The physician measures the angle of dorsiflexion in the ankle joint. The mobile application was used for the testing (Banwell et al., 2019; Williams et al., 2013). Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 204 Science of Gymnastics Journal All three groups were tested before training without warming up. Results were collected in an Excel spreadsheet and subsequently subjected to statistical analysis using software SAS® Enterprise Guide® (SAS Institute Inc., USA). Non-parametric tests were used. The difference in the mean values for the right ankle joint and the left ankle joint between three groups has been evaluated with Kruskal-Wallis one-way analysis of variance. To assess the difference in the mean values for the right ankle joint and the left ankle joint between two groups, Wilcoxon scores have been calculated using Wilcoxon Rank Sum Test. Pearson's correlation coefficient was used to test the correlation. RESULTS Table 1 Mean range of motion dorsiflexion (ROM) in artistic gymnasts, rhythmic gymnasts and athletes. Average ROM (°) Right Left Group 33.00 30.50 Artistic gymnasts Min Mean 47.32 44.75 Max 63.00 65.00 Range 30.00 34.50 QRange 8.00 10.00 Rhythmic gymnasts Min 36.00 35.20 Mean 44.32 43.41 Max 51.00 49.50 Range 15.00 14.30 QRange 6.00 3.30 Athletes Min 29.00 29.00 Mean 44.27 42.32 Max 56.00 54.00 Range 27.00 25.00 QRange 11.00 9.00 Table 2 Mean range of motion dorsiflexion (ROM) in male and female. Average ROM (°) Right Left Group Sex 33.00 32.00 Artistic gymnasts Female Min Mean 47.88 44.45 Max 57.00 62.50 Range 24.00 30.50 QRange 6.50 6.90 Male Min 36.00 30.50 Mean 46.76 45.05 Max 63.00 65.00 Range 27.00 34.50 QRange 9.20 11.00 Rhythmic gymnasts Female Min 36.00 35.20 Mean 44.32 43.41 Max 51.00 49.50 Range 15.00 14.30 QRange 6.00 3.30 Athletes Female Min 29.00 29.00 Mean 43.30 40.80 Max 56.00 54.00 Range 27.00 25.00 QRange 14.00 7.00 Male Min 36.00 36.00 Mean 45.08 43.58 Max 50.00 52.00 Range 14.00 16.00 QRange 10.00 8.50 Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 205 Science of Gymnastics Journal Figure 1. Comparison between artistic gymnasts, rhythmic gymnasts and athletes. Table 3 Statistical difference between groups of artistic gymnasts (AG), rhythmic gymnasts (RG), and athletes (AT). All Female Male GROUPS Right Left Right Left Right Left AG - RG 0.0417 0.3883 0.0231 0.4421 x x AG - AT 0.0904 0.1865 0.0907 0.1755 0.3708 0.3515 RG - AT 0.3848 0.2371 0.4532 0.0886 x x The mean dorsiflexion range of motion in artistic gymnasts was 47.32 ° in the right ankle joint and 44.75 ° in the left ankle joint. The mean dorsiflexion range of motion in rhythmic gymnasts was 44.32° in the right ankle joint and 43.41° in the left ankle joint. The mean dorsiflexion range of motion in young athletes was 44.27° in the right ankle joint and 42.32° in the left ankle joint. The results can be seen in Table. 1 The mean dorsiflexion range of motion in artistic gymnasts was 47.88 ° in the right ankle joint and 44.45 ° in the left ankle joint. The mean dorsiflexion range of motion in male artistic gymnasts was 46.76 ° in the right ankle joint and 45.05 ° in the left ankle joint. The mean dorsiflexion range of motion in rhythmic gymnasts was 44.32° in the right ankle joint and 43.41° in the left ankle joint. The mean range of motion of dorsiflexion in young female athletes was 43.30 ° in the right ankle joint and 40.8 ° in the left ankle joint. The mean dorsiflexion range of motion in young male athletes was 45.08 ° in the right ankle joint and 43.58 ° in the left ankle joint. The results can be seen in Table. 2. Furthermore, we compared the statistical significance at α-0.05 significance level -0.05. There was a significant difference in favor of artistic gymnasts compared to Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 206 Science of Gymnastics Journal rhythmic gymnasts in the right ankle joint (p <0.04). In the left ankle joint, no significant differences were found (p-0.38). There were no statistically significant differences between artistic gymnasts and athletes in the right ankle joint (p-0.09) and the left ankle joint (p-0.19). No significant differences were found between rhythmic gymnasts and athletes in the right ankle joint (p-0.38) or the left ankle joint (p-0.24). A significant difference was detected in favor of female artistic gymnasts compared to rhythmic gymnasts (p-0.02) in the right ankle joint and no significant difference (p- 0.44) in the left ankle joint. There were no significant differences between artistic gymnasts and athletes in the right ankle joint (p-0.09) and the left ankle joint (p- 0.18). A significant difference was not detected between male artistic gymnasts and male athletes in the right ankle joint (p- 0.37) or the left ankle joint (p-0.35). There was no significant difference between rhythmic gymnasts and female athletes in the right ankle joint (p-0.45) and the left ankle joint (p-0.08). The results can be seen in Table 2 Dorsiflexion in artistic gymnasts did not correlate with age (r-0.13-0.19), weight (r- 0.28-0,29), and sport age (r- 0.21-0.31). The range of motion of dorsiflexion in rhythmic gymnasts did not correlate with age (r-0.36), weight (r- 0.04-0.12), and sport age (r-0.22-0.30). In the young athlete’s dorsiflexion range of motion did not correlate with age RL (r-0.20), weight RL (r-0.13-0,15), and sport age (r-0.12- 0.20) DISCUSSION Gymnastic training develops strength, flexibility, concentration, balance, precision of movement, and speed in young gymnasts. Young gymnasts dedicate a considerable amount of time to training (Zetaruk, 2000). Physical loading during training time stimulates changes in the musculoskeletal system. These changes have positive or negative effects. Maintaining a balance between flexibility and strength, training modification, and correct training periodization reduces the risk of injuries in the case of excessive training. The highest mean range of motion for dorsiflexion was confirmed in the group of young gymnasts. These findings support the assumption that gymnastic training leads to adaptation of the musculoskeletal system including the dorsiflexion range of motion in the ankle joint. Despite a higher mean of dorsiflexion range of motion in the ankle joint, it still did not lead to hypermobility in young gymnasts. The appearance of dorsiflexion hypermobility in all groups was influenced by individual flexibility in the various joints rather than by the type of sport itself. A significant difference was found between female artistic gymnasts and rhythmic gymnasts. We assumed a greater dorsiflexion range of motion in the ankle joint in rhythmic gymnasts. This assumption was not confirmed; rhythmic gymnasts had a significantly lower dorsiflexion range of motion in the ankle joint. A possible explanation for this finding is that rhythmic gymnasts perform most of the movement in plantar flexion rather than in dorsiflexion in the ankle joint. The musculoskeletal system of rhythmic gymnasts lacks an adaptive stimulus to increase the range of motion of dorsiflexion. The mean range of motion of dorsiflexion in the ankle joint in artistic gymnasts was greater than in athletes. However, the difference was not statistically significant. Gymnastic training requires more flexibility training than athletic training. On the other hand, athletic training focuses on numerous activities that involve the ankle joint in various directions. It can lead to natural adaptation of a range of motion in the ankle joint. In the training of young athletes, adequate range of motion in the ankle joint is essential for sports performance, especially in sprints and jumps. In a previous study (Líška et al., 2021), we focused on comparing the range of Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 207 Science of Gymnastics Journal motion of judo and football players. The mean dorsiflexion range for judoists was 43.15-43.90° and for football players 41.02- 42.09°. Compared to gymnasts in our study, the dorsiflexion was lower, which may indicate that gymnastic training involves more complex training for ankle joint than judo and soccer. Systematic sports training in different disciplines leads to functional and structural adaptation of the human organism. In a systematic review, Jürimäe (Jürimäe et al., 2018) monitored the influence of gymnastic training on one group compared to another group without gymnastic training. The group of gymnasts had better bone density, lower body weight, delayed pubertal development, and lower levels of some hormones. Bukva et al. (2019) examined the association between generalized hypermobility in gymnasts. To examine the gymnasts, Beighton score was used. The sample consisted of 24 rhythmic gymnasts. The most common injury was lower back pain, followed by knee, shoulder, hip, and ankle injuries. The number of training years was correlated with the prevalence and incidence of injuries (P<0.001). The number of training hours per week was not correlated with the incidence of injuries (P>0.05). Young gymnasts are at an increased risk of injury due to overload. An overload injury occurs when there is an inadequate ratio between the training load and regeneration. In young gymnasts, inadequate body adaptation to the training load and inadequate range of motion at the ankle joint increase the risk of injury. Sweeney et al. (Sweeney et al., 2019) examined the relationship between flexibility and lower back pain in rhythmic gymnasts: 30 of 67 gymnasts experienced lower back pain in 5 years. Gymnasts who experienced lower back pain were those with higher age (11.7 vs 13.7, P = 0.005), weight (37.5 vs 43.4 kg, P = 0.049) and training time (19.1 vs 22.4 h / week, P = 0.017). Gymnasts use various training methods to increase their range of motion. Dallas et al. (Dallas et al., 2014) examined the acute effect on flexibility in gymnasts using static stretching, proprioceptive, neuromuscular facilitation, and stretching on a vibrating platform. The most significant changes in the range of motion were found in the group using proprioceptive neuromuscular facilitation. In our study, the weight-bearing lunge test was used to measure dorsiflexion in the ankle joint in the closed kinematic chain as a pilot test in gymnastics. This test was used in other sports, for example, in football. The range of motion of dorsiflexion in the ankle joint changes during the season depending on the level of physical activity. Moreno- Peréz (2020) examined this issue. The sample consisted of 45 football players tested before and after the match to determine the acute effect of physical activity. The long-term effect was tested before, during and after the competitive season. The dorsiflexion range of motion in the ankle joint in the closed kinematic chain was at the highest level. The preseason values were higher than the midseason values (8.1% dominant lower limb and 9.6% non-dominant lower limb). Post- season tests showed a significant decrease in dorsiflexion range of motion in the ankle joint (13.8% dominant lower limb, 12.5% non-dominant lower limb). A decrease in the dorsiflexion range of motion occurred in 30% of football players. An increase in dorsiflexion range of motion after the match indicates the immediate effect of physical activity (5.8% dominant lower limb). This increase in the dorsiflexion range of motion decreased during the next 48 hours. According to Moreno-Peréz, the decrease in the dorsiflexion range of motion in the ankle joint is related to a higher risk of injury during the mid-season and post- season period. Backman et al. (2011) also examined the relationship between injuries and the limited range of motion of dorsiflexion in the ankle joint. The sample consisted of 75 junior basketball players monitored during one season. Twelve of them experienced patellar tendinopathy Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 208 Science of Gymnastics Journal during the season. They also had lower dorsiflexion range of motion in the ankle joint (P=0.038) in the dominant lower limb and in the nondominant lower limb (P = 0.024). Another data shows that players with dorsiflexion range of motion in the ankle joint less than 36.5° were at 18.5% to 29.4% higher risk of suffering patellar tendinopathy in one year compared to players with dorsiflexion range of motion in the ankle joint greater than 36.5° (1.8% - 2.1%). Macrum et al. (2012) examined the effect of limited dorsiflexion range of motion in ankle joints in a squat. The sample consisted of 30 participants who performed no-restriction squat-simulating motion restriction in the ankle joint. Limiting the range of motion in the ankle joint led to an increase in the knee valgus. Simultaneously, simulating motion restriction in the ankle joint is related to a lower activation of the m.quadriceps femoris and a higher activation of the m.soleus. The optimal range of motion in the ankle joint in the closed kinematic chain in gymnasts is an important issue to be determined in future studies by examining the relationship between gymnastic training and the range of motion in the ankle joint. Determining the optimal range of motion of dorsiflexion enables setting the optimal reference values and advances the gymnastics training process. Training time was the limiting factor in influencing the validity of the tests in both groups of gymnasts in comparison to athlets. The mean training time of young athletes has been lower compared to gymnasts of the same age. However, the number of years of training did not correlate with the overall effect on the range of motion of dorsiflexion in the ankle joints in any group. To confirm the validity of this statement, it is important to test the potential relationship between different groups of professional gymnasts and athletes. Another limitation of our study was the relatively small sample. CONCLUSIONS A greater dorsiflexion range of motion in a closed kinematic chain in the ankle joint was detected in young gymnasts compared to rhythmic gymnasts. There was no significant difference between artistic gymnasts and athletes. REFERENCES Antonio, D. H., & Magalhaes, C. S. (2018). Survey on joint hypermobility in university students aged 18-25 years old. Advances in Rheumatology (London, England), 58(1), 3. https://doi.org/10.1186/s42358-018-0008-x Backman, L. J., & Danielson, P. (2011). Low range of ankle dorsiflexion predisposes for patellar tendinopathy in junior elite basketball players: A 1-year prospective study. The American Journal of Sports Medicine, 39(12), 2626–2633. https://doi.org/10.1177/036354651142055 2 Banwell, H. A., Uden, H., Marshall, N., Altmann, C., & Williams, C. M. (2019). The iPhone Measure app level function as a measuring device for the weight bearing lunge test in adults: A reliability study. Journal of Foot and Ankle Research, 12, 37. https://doi.org/10.1186/s13047-019-0347-9 Bradshaw, E. J., & Hume, P. A. (2012). Biomechanical approaches to identify and quantify injury mechanisms and risk factors in women’s artistic gymnastics. Sports Biomechanics, 11(3), 324–341. https://doi.org/10.1080/14763141.2011.65 0186 Bukva, B., Vrgoč, G., Madić, D. M., Sporiš, G., & Trajković, N. (2019). Correlation between hypermobility score and injury rate in artistic gymnastics. The Journal of Sports Medicine and Physical Fitness, 59(2), 330–334. https://doi.org/10.23736/S0022- 4707.18.08133-1 Čillík, I., & Willweber, T. (2018). Influence of an exercise programme on level of coordination in children aged 6 to 7. Journal of Human Sport and Exercise, Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 209 Science of Gymnastics Journal 13. https://doi.org/10.14198/jhse.2018.132.14 Dallas, G., Smirniotou, A., Tsiganos, G., Tsopani, D., Di Cagno, A., & Tsolakis, C. (2014). Acute effect of different stretching methods on flexibility and jumping performance in competitive artistic gymnasts. The Journal of Sports Medicine and Physical Fitness, 54(6), 683–690. De Carli, A., Mossa, L., Larciprete, M., Ferretti, M., Argento, G., & Ferretti, A. (2012). The gymnast’s shoulder MRI and clinical findings. The Journal of Sports Medicine and Physical Fitness, 52(1), 71– 79. Desai, N., Vance, D. D., Rosenwasser, M. P., & Ahmad, C. S. (2019). Artistic Gymnastics Injuries; Epidemiology, Evaluation, and Treatment. The Journal of the American Academy of Orthopaedic Surgeons, 27(13), 459–467. https://doi.org/10.5435/JAAOS-D-18- 00147 Edouard, P., Steffen, K., Junge, A., Leglise, M., Soligard, T., & Engebretsen, L. (2018). Gymnastics injury incidence during the 2008, 2012 and 2016 Olympic Games: Analysis of prospectively collected surveillance data from 963 registered gymnasts during Olympic Games. British Journal of Sports Medicine, 52(7), 475– 481. https://doi.org/10.1136/bjsports-2017- 097972 Hart, E., Meehan, W. P., Bae, D. S., d’Hemecourt, P., & Stracciolini, A. (2018). The Young Injured Gymnast: A Literature Review and Discussion. Current Sports Medicine Reports, 17(11), 366–375. https://doi.org/10.1249/JSR.000000000000 0536 Jürimäe, J., Gruodyte-Raciene, R., & Baxter-Jones, A. D. G. (2018). Effects of Gymnastics Activities on Bone Accrual during Growth: A Systematic Review. Journal of Sports Science & Medicine, 17(2), 245–258. Kerr, G. (1990). Preventing gymnastic injuries. Canadian Journal of Sport Sciences = Journal Canadien Des Sciences Du Sport, 15(4), 227. Knorr, A. (2014). Positive and negative skeletal adaptation in young gymnasts. The Nurse Practitioner, 39(5), 38–47. https://doi.org/10.1097/01.NPR.000044578 2.10109.1c Kochanowicz, A., Niespodziński, B., Marina, M., Mieszkowski, J., Biskup, L., & Kochanowicz, K. (2018). Relationship between postural control and muscle activity during a handstand in young and adult gymnasts. Human Movement Science, 58, 195–204. https://doi.org/10.1016/j.humov.2018.02.0 07 Kolar, P., Kobesova, A., Valouchova, P., & Bitnar, P. (2013). Dynamic Neuromuscular Stabilization. Assessment methods. In Recognizing and Treating Breathing Disorders: A Multidisciplinary Approach (pp. 93–98). Scopus. https://doi.org/10.1016/B978-0-7020- 4980-4.00008-3 Líška, D., Liptaková, E., Baťalík, L., & Rutkowski, S. (2021). The ankle joint dorsiflexion range of motion in the closed kinematic chain of judokas and football players – pilot study. Archives of Budo, 17(0). 7 Macrum, E., Bell, D. R., Boling, M., Lewek, M., & Padua, D. (2012). Effect of limiting ankle-dorsiflexion range of motion on lower extremity kinematics and muscle- activation patterns during a squat. Journal of Sport Rehabilitation, 21(2), 144–150. https://doi.org/10.1123/jsr.21.2.144 Marcolin, G., Rizzato, A., Zuanon, J., Bosco, G., & Paoli, A. (2019). Expertise level influences postural balance control in young gymnasts. The Journal of Sports Medicine and Physical Fitness, 59(4), 593– 599. https://doi.org/10.23736/S0022- 4707.18.08014-3 Moreno-Pérez, V., Soler, A., Ansa, A., López-Samanes, Á., Madruga-Parera, M., Beato, M., & Romero-Rodríguez, D. (2020). Acute and chronic effects of competition on ankle dorsiflexion ROM in professional football players. European Journal of Sport Science, 20(1), 51–60. Líška D., Kremencký J.: THE LEVEL OF DORSIFLEXION IN YOUNG GYMNASTS … Vol. 14, Issue 2: 201 - 210 Science of Gymnastics Journal 210 Science of Gymnastics Journal https://doi.org/10.1080/17461391.2019.16 11930 Nassib, S. H., Mkaouer, B., Riahi, S. H., Wali, S. M., & Nassib, S. (2020). Prediction of Gymnastics Physical Profile Through an International Program Evaluation in Women Artistic Gymnastics. Journal of Strength and Conditioning Research, 34(2), 577–586. https://doi.org/10.1519/JSC.000000000000 1902 Schmidt, H., Pedersen, T. L., Junge, T., Engelbert, R., & Juul-Kristensen, B. (2017). Hypermobility in Adolescent Athletes: Pain, Functional Ability, Quality of Life, and Musculoskeletal Injuries. The Journal of Orthopaedic and Sports Physical Therapy, 47(10), 792–800. https://doi.org/10.2519/jospt.2017.7682 Sweeney, E. A., Daoud, A. K., Potter, M. N., Ritchie, L., & Howell, D. R. (2019). Association Between Flexibility and Low Back Pain in Female Adolescent Gymnasts. Clinical Journal of Sport Medicine: Official Journal of the Canadian Academy of Sport Medicine, 29(5), 379–383. https://doi.org/10.1097/JSM.00000000000 00660 Williams, C. M., Caserta, A. J., & Haines, T. P. (2013). The TiltMeter app is a novel and accurate measurement tool for the weight bearing lunge test. Journal of Science and Medicine in Sport, 16(5), 392– 395. https://doi.org/10.1016/j.jsams.2013.02.00 1 Zetaruk, M. N. (2000). The young gymnast. Clinics in Sports Medicine, 19(4), 757–780. https://doi.org/10.1016/s0278- 5919(05)70236-2 Corresponding author: Dávid Líška Matej Bel University Tajovkeho 40 Banska Bystrica Banskobistrycky 974 01 Slovakia Tel.: +48695892404 E mail: david.liska27@gmail.com Article received: 3.8.2021 Article accepted: 14.12.2021