Morphological similarities and differences of young players from selected sport team games

Introduction: Body physique is an important determinant of sports success. Knowledge in this area enables the effective selection of players for various sports disciplines. Aim: Using a multidimensional perspective, to determine the degree of variation in the body physique of athletes from four sports disciplines: American football, football, volleyball and handball. Materials and methods: The research was carried out in 2017 in sport clubs operating in the Lower Silesia Voivodship. The research group consisted of 125 male players, with a mean age of 16.27 years. They represented 4 sports disciplines and included 22 American football players, 30 football players, 49 handball players and 24 volleyball players. In the analysis, the measurements of height and weight were used as well as the Body Max Index, calculated with the following formula: body weight [kg]/body height [m]2 Results: The American football players had the highest body weight and the highest BMI. The handball and volleyball players were the tallest. The football players were characterised by the lowest body weight. Conclusions: Each of the analysed sports disciplines prefers players with a different body physique. Nevertheless, a greater similarity between the handball and volleyball players can be observed. American football players are more different morphologically, whereas football players are the least similar to the players from the other disciplines. The results of the study will facilitate both players' and coaches' decision-making process regarding the change of the sports discipline and the choice of a new one, if such need arises

The sex effects on changes in jump performance following an isometric back squat conditioning activity in trained adults

There are limited data concerning the disparity between males and females in post-activation performance enhancement (PAPE) based on isometry. Therefore, this study aimed to establish if sex differences exist in the PAPE effect on jump height. The study included 30 males and 15 females aged between 19 and 25, with relative strength in the back squat of at least 110% of body weight and a minimum of 3 years of resistance training experience. A baseline countermovement jump (CMJ) was performed, and the PAPE protocol, which involved three 4-s sets of isometric full-back squats with a 1-min rest interval, was introduced. Five CMJs were performed over the following 9 minutes in 2 minutes rest intervals. Changes (Δ) towards the baseline and each jump height results were calculated and analyzed in the absolute (cm) and relative (%) approach. The repeated measures ANOVA with sex as between-groups effect and time of the changes as within-group effect were conducted. Results showed statistically significant interaction (sex×time) in absolute changes (Δ cm) (F = 2.50, η2 = 0.05, p = 0.0447), which indicated that the sex effect has changed over time. Post-hoc test showed that during the first 3 minutes, men and women benefited equally, but in the fifth and seventh minutes, the observed changes were greater in men, thus close to significance (p = 0.0797, p = 0.0786), and in the last minute, the difference was statistically significant (p = 0.0309). Also, a statistically significant interaction effect was observed for relative changes (Δ %) (F = 4.22, η2 = 0.09, p = 0.0027). At the beginning (the first and third minutes), changes in females were greater than in males, but the differences were insignificant. However, after 5 minutes, the decrease in females was observed with statistically significant differences in the last minute compared to males (p = 0.0391). Chi-Squared analysis indicated that the time to peak performance was insignificant (χ2 = 7.45, p = 0.1140) in both sexes. The introduced PAPE protocol based on isometry improved jump height in both sexes, with performance enhancement recorded in the third-minute post-activation. However, performance decreased in females over the next 6 minutes, while it was maintained in the male group. Despite the generally positive short-term effects of the protocol on females, the usefulness of the protocol is limited

Predictors of injuries among young players team games

Introduction: The aim of the study was to determine the relationship between the basic somatic traits and the metric age and training experience of players and the injuries suffered. Material and methods: 125 male athletes aged between 14 and 19 years old were examined. They represented 4 sports disciplines. Respondents practicing American football (22 players), respondents playing football (30 players), respondents practicing handball (49 players), respondents practicing volleyball (24 players). All players belonged to the category of juniors. The research tool was a short questionnaire, in which the surveyed person gave their name and date of birth. The next part of the questionnaire contained questions about the sport practiced. The next stage of the study was the measurement of body height, which was performed with a Swiss anthropometer, and body weight was measured on electronic weight. The Body Mass Index (BMI) was calculated from the formula: body weight [kg]/height [m]2. Results: In all analysed sports, body weight is the most important for the number of injuries. BMI is important in all team sports. Slim body reduces the number of injuries by about 2-8 injuries. From among the analysed variables the body structure features have an influence on the number of injuries. There were no correlations between the age of competitors and their training experience. The number of injuries depends mainly on the body weight of the player. Conclusion: Football players suffered the most injuries during their career, followed by handball players. Average injuries of American football players and volleyball players were much lower and similar to each other. While analysing the whole group of the respondents, it was observed that among the variables discussed above, the weight of competitors has the strongest influence on the number of injuries suffered. The body weight has the strongest statistically significant effect on injuries in American football, and secondly in volleyball. The weakest, statistically insignificant, body weight affects injuries in footballers

Intentional dehydration of taekwondo practitioners in relation to their stamina and motor skills level

Introduction In sports where competitors are divided into weight classes, a problem of obtaining the desired body mass on the competition day occurs. This issue is present primarily in martial arts, with an exception of fencing. Therefore, adjusting body mass is a component of the training process and happens cyclically due to participation in tournaments (Sterkowicz, 2006). These procedures are used most frequently before competitions in order to fit into the limits of a lower or higher weight class (Sterkowicz et al., 2005). Taekwondo tournaments participants are divided into weight classes, just like is wrestling, judo, and other martial arts. The purpose of the division is to ensure fairness of the fights by selecting opponents of similar morphological and physiological characteristics. Nonetheless, decreasing body mass for the purpose of qualifying into the lower weight class is a frequent phenomenon (Janiszewska et al., 2012). A large percentage of the competitors reduces body mass during the short period preceding the official weighting before a tournament, then go back to the natural body mass during the several hours before the tournament starts (Kazemi, 2005; Fleming, 2009). It is possible that the competitors reduce body mass as a result of discarding excessive fat reserves in specific body parts. However, very frequently it is competitors of very low fat body content rapidly reducing body mass before a tournament solely through dehydration, since it is the only way to qualify to the lower weight class (Shirreffs, 2009). Rapid and quick body mass reduction leading to dehydration, however, is not without influence on body functions. Reports on the problem suggest that occurring negative physiological consequences result in motor skill changes. Nonetheless, there are no reports unequivocally naming the type of motor skills connected to dehydration. Thus, the purpose of the paper was to determine the influence of intentional dehydration on the level of the following motor skills: stamina (strength), coordination (simple reaction time and upper limb movement speed), and speed of taekwondo practitioners

Change of the precision of hand movements in young men after short-term (anaerobic) exercise

Background: Physical exercise causes disturbances of body homoeostasis resulting in fatigue. This affect the quality of motor activity, including precision of hand movement. The objective of the work was to evaluate the effect of a short-term (anaerobic) physical exercise on hand movement in men in static and dynamic conditions. Materials &methods: The study group comprised of 52 young men aged 20.44±7.87 years old. Heartbeat frequency, systolic and diastolic blood pressure were measured. Precision of hand movement was studied with the use of the MLS module from the Vienna Test System. Tests of precise hand movements were conduced in static and dynamic conditions. A number of errors committed was analysed. Tests were performed with a dominant hand, twice: before and after an anaerobic exercise. The exercise test was to perform a maximum number of arm flexes in frontal support (press-ups), until denied. Results: Comparison of test results before and after the exercise indicated a statistically significant increase of hand tremor in statics and no changes in dynamics after the exercise. This occurrence was manifested by a number of errors made. Using multiple regression, it was shown that hand tremor in statics is related to body built. Higher values of height and body mass correlated with a greater number of errors. A statistically significant impact of resting heartbeat frequency on a number of errors in statics was also observed. In dynamic conditions, a relationship between hand tremor and a volume of work performed and the resultant heartbeat frequency was detected. The increase in number of flexes by one causes the increase in number of errors by two. Conclusion: Physical exercise significantly affects hand precision in statics in the students studied. Impact of physical exercise on a greater number of errors committed in a dynamic test was not observed

Effects of Combination Movement Patterns Quality and Physical Performance on Injuries in Young Athletes

Identifying the factors associated with the injuries is crucial to prevention, enabling apply effective methods to reduce injuries frequency. This is especially important for young athletes for whom an injury may impair development or prematurely end a sports career. Therefore, the objective of this study is to examine if the movement patterns quality and physical performance simultaneously affected injury occurrence in young athletes. The participants were 176 athletes aged 22.44 ± 1.64. The injury data were collected from the 12 months retrospective period. The functional movement screen test was conducted to assess the quality of movement patterns, and the physical performance tests were done for assessing strength, power, flexibility, and balance. Results showed relationships between movement patterns quality and flexibility with injuries. The receiver operating characteristic curve demonstrated growing injury frequency for 14 ≥ FMS and 21 cm ≥ Sit-and-reach test. Rank Transform ANOVA revealed a simultaneous effect of movement quality (F = 11.5361; p = 0.0008) and flexibility (F = 8.0514; p = 0.0050) on an injury. Post-hoc tests indicated that the group with low-quality movement patterns combined with a low level of flexibility is the most frequently injured (p < 0.05). It is recommended to include in training, routine exercises improving movement patterns and flexibility to prevent injuries

The Impact of Physical Performance on Functional Movement Screen Scores and Asymmetries in Female University Physical Education Students

Association between physical performance and movement quality remains ambiguous. However, both affect injury risk. Furthermore, existing research rarely regards women. Therefore, this study aimed to assess the impact of physical performance components on FMS scores and asymmetries among young women—University Physical Education Students. The study sample was 101 women, 21.72 ± 1.57 years, body mass index 21.52 ± 2.49 [kg/m2]. The FMS test was conducted to assess the movement patterns quality. Physical performance tests were done to evaluate strength, power, flexibility. Flexibility has the strongest correlation with FMS overall (r = 0.25, p = 0.0130) and single tasks scores. A higher level of flexibility and strength of abdominal muscles are associated with fewer asymmetries (r = −0.31, p = 0.0018; r = −0.27, p = 0.0057, respectively). However, the main findings determine that flexibility has the strongest and statistically significant impact on FMS overall (ß = 0.25, p = 0.0106) and asymmetries (ß = −0.30, p = 0.0014). Additionally, a significant effect of abdominal muscles strength on FMS asymmetries were observed (ß = −0.29, p = 0.0027). Flexibility and abdominal muscles strength have the most decisive impact on movement patterns quality. These results suggest possibilities for shaping FMS scores in young women

Acute Effect of Short Intensive Self-Myofascial Release on Jump Performance in Amateur Athletes: A Randomized Cross-Over Study

Searching for effective methods to maximize physical performance that can be utilized during warm-ups is challenging in modern sports. This study aimed to investigate the effect of a short and intensive self-myofascial release (SI-SMR) on jumps in amateur, collegiate athletes. The study sample consists of 30 subjects with an average age of 21.8 years. The tests conducted included a squat jump (SJ), countermovement jump (CMJ), and drop jump (DJ). In the first week, half of the participants performed a standardized warm-up with additional short (15 s per lower limb muscle group) and intensive (20 reps/15 s) SMR and then performed jump tests. The other half performed a standard warm-up. The following week the groups switched interventions. The results revealed a tendency for all jump test parameters (height, force, and power), the reactive strength index, and stiffness to improve with SI-SMR, but the differences were small and insignificant. A dependent t-test for paired samples revealed that only SJ height improvement (+0.96 ± 2.63 cm) reached statistical significance (p = 0.04), but the small ES (ES = 0.14) could have attenuated this result. When a two-way mixed ANOVA was applied, the differences were insignificant. SI-SMR was ineffective in the direct improvement of jump performance. Although SI-SMR had no adverse effects, athletes should focus on specific preparations for sports competitions instead of using an SI-SMR protocol

Risk of Single and Multiple Injuries Due to Static Balance and Movement Quality in Physically Active Women

Background: Static balance is a reliable indicator of the musculoskeletal and nervous systems, which is a basis for movement stabilization development. The disorders in this area may increase injury risk (IR). This study investigated the musculoskeletal injury risk due to static balance and movement quality regarding single and multiple injury occurrences in physically active women. Methods: The study sample was 88 women aged 21.48 ± 1.56. The injury data were obtained with a questionnaire, and Deep Squat (DS), In-line lunge (IL), and Hurdle Step (HS) tests were conducted. Static balance was assessed with a stabilometric platform measured center of gravity area circle (AC) and path length (PL) with open (OE) and closed eyes (CE), maintaining a standing position for the 30 s. Results: The logistic regression models revealed the general injury occurrence was predicted by AC-CE (OR = 0.70; p = 0.03) and IL (OR = 0.49; p = 0.03), and the two-factor model AC-CE*IL, (OR = 1.40; p < 0.01). When the single injury was predicted by the same factors AC-CE (OR = 0.49; p < 0.01), IL (OR = 0.36; p = 0.01), and AC-CE*IL (OR = 1.58; p < 0.01). Conclusion: Static balance and movement stability predict musculoskeletal injury risk alone and in one model. A further study is needed to verify the efficiency of indicated factors in prospective terms. Using both quantitative and qualitative tests could be helpful in IR prediction

The effectiveness of isometric protocols using an external load or voluntary effort on jump height enhancement in trained females

Abstract This study aimed to examine the effectiveness of isometric post-activation performance enhancement protocols using an external load (EXL) or voluntary effort (VE) on jump height (JH) in trained females divided into EXL (n = 15), VE (n = 14), and control (CON; n = 12) groups. JH was assessed using countermovement jumps at baseline and the third, fifth, seventh, and ninth minutes after the protocols. The EXL performed three sets of back squats with a 70%-repetition maximum load for four seconds, with one-minute breaks. The VE performed three sets of pushing against an immovable bar in the back squat position for five seconds, with one-minute breaks. The CON group ran on a treadmill at 6 km/h for four minutes. A RM-ANOVA showed a significant interaction for group-time (p < 0.01). The EXL protocol provided JH improvement at the third minute compared to baseline (p = 0.01), though it decreased in subsequent minutes (p < 0.05). JH declined in the VE group at the third and fifth minutes (p < 0.05), then peaked, surpassing baseline, after nine minutes (p = 0.04). No significant differences were found between the protocols in the relative effect (best—baseline) (p = 0.09), though the EXL group appeared to gain more (effect size [ES] = 0.76). Both protocols improved JH, but caution is required due to peak performance time and potential JH reduction