Elite Junior Research Articles

Selected Kinematic Characteristics Analysis of Knee and Ankle Joints During Block Jump Among Elite Junior Volleyball Players

Selected Kinematic Characteristics Analysis of Knee and Ankle Joints During Block Jump Among Elite Junior Volleyball Players

Does a higher training age attenuate injury risk in junior elite rugby league players?

Our aim was to determine the relationships between three different training ages – TA domains (Rugby League specific – RLTA; Resistance training – RTA; Cardiovascular training – CVTA) on injury ris...

MRI Bone Marrow Edema Signal Intensity: A Reliable and Valid Measure of Lumbar Bone Stress Injury in Elite Junior Fast Bowlers.

Comparative reliability and prospective validity. First, to evaluate the reliability of four methods of assessing magnetic resonance imaging (MRI) bone marrow edema (BMO) of the posterior vertebral arch of the lumbar vertebrae of elite junior fast bowlers. Second, to evaluate the validity of the most reliable method for the early detection of lumbar bone stress injury. MRI has demonstrated utility in identifying BMO in lumbar vertebrae. Methods to grade the severity of BMO may provide valuable insight to inform clinical management, particularly in elite athletes where detection of early-stage bone stress may prevent progression to more severe and costly bone stress injury. Sixty-five male elite junior fast bowlers had repeat MRI scans during a cricket season. A subset of 19 bowlers' images were reassessed by experienced musculoskeletal radiologists to determine intra- and inter-rater reliability. All images were aligned with independent medical records of lower back symptoms and diagnosed bone stress injuries to establish the relationship of BMO and lumbar bone stress injury. Clinical detection of abnormal BMO, whether the pars region of the vertebra was considered in its entirety or subdivided into regions, had fair-to-moderate inter-rater reliability, and fair-to-almost perfect intra-rater reliability. Measurement of BMO signal intensity using an imaging software tool had excellent intra-rater and inter-rater reliability (ICC = 0.848, 0.837). BMO signal intensity was positively associated with subsequent LBSI (P < 0.001), and differentiated between asymptomatic and symptomatic bowlers (P < 0.001). Measurement of BMO signal intensity using an imaging software tool proved a reliable and valid measure of the severity of lumbar bone stress injury in elite junior fast bowlers. 2.

Variation in load in elite junior AF players across the week in a 24-week season is associated with changes in wellness (mood and soreness)

Variation in load in elite junior AF players across the week in a 24-week season is associated with changes in wellness (mood and soreness)

Does a higher training age attenuate injury risk in junior elite rugby league players?

Our aim was to determine the relationships between three different training ages – TA domains (Rugby League specific – RLTA; Resistance training – RTA; Cardiovascular training – CVTA) on injury ris...

Absolute and Relative Load and Injury in Elite Junior Australian Football Players Over 1 Season.

To investigate the association between training and match loads and injury in elite junior Australian football players over 1 competitive season. Elite junior Australian football players (n = 290, age 17.7 [0.3] y, range 16-18y) were recruited from the under-18 state league competition in Victoria to report load and injury information. One-week load (session rating of perceived exertion multiplied by duration) and all time-loss injuries were reported using an online sport-injury surveillance system. Absolute load measures (weekly sums) enabled the calculation of relative measures such as the acute:chronic workload ratio. Load measures were modeled against injury outcome (yes/no) using a generalized estimating equation approach, with a 1-wk lag for injury. Low (<300arbitrary units [au]) and high (>4650au) 1-wk loads were associated with significantly higher risk of injury. Furthermore, low (<100au) and high (>850au) session loads were associated with a higher risk of injury. High strain values (>13,000) were associated with up to a 5-fold increase in the odds of injury. There was a relatively flat-line association between the acute:chronic workload ratio and injury. This study is the first investigation of elite junior athletes demonstrating linear and nonlinear relationships between absolute and relative load measures and injury. Coaches should focus player loads on, or at least close to, the point at which injury risk starts to increase again (2214au for 1-wk load and 458au for session load) and use evidence-based strategies across the week and month to help reduce the risk of injury.

Assessment of elite junior tennis serve and return practice: A cross-sectional observation

ABSTRACTPractice tasks that more closely represent the demands of competition are thought to augment skill learning and transfer. This study observed the serve and return performances of junior grand slam tennis and used this benchmark to evaluate the representativeness of serve and return practice among elite junior tennis players. The serve and return behaviour of 26 junior tennis players competing in junior Australian Open grand slam matches were observed and compared with the serve and return practice behaviours of 12 elite junior tennis players over an 8-week period. The variables measured included the number of serves/returns landing in, serve/return type, serve direction and the variability of practised skills. Serve and return practice contributed to <13% of total practice time, with each skill predominately practised in isolation. Compared to the matchplay benchmark, players typically had less success (i.e., fewer serves/returns landing in the court), were less variable in shot selection and hit fewer serves to the extremities of the service box. As task representativeness increased fewer differences between practice and matchplay were observed. Tennis serve and return practice could be improved by better simulating specific competition affordances, providing greater opportunities to practice serve/return tactics and/or increasing the variability of practised skills.

A One-Season Prospective Study of Illnesses, Acute, and Overuse Injuries in Elite Youth and Junior Track and Field Athletes.

Background: In high-level adult athletes, injury incidences and characteristics have been reported during international championships and during one season. Youth track and field athletes are also exposed to injury risk, although less information is available on this specific population, as well as on illness risk.Aim: To determine the prevalence of health problems (i.e., illnesses, acute, and overuse injuries) in high level Youth and Junior Track & Field athletes.Method: During the 2015–16 athletics season (30 weeks from December 2015 to July 2016), we conducted a prospective cohort study on a population of Youth and Junior Irish national level athletes, during which athletes were asked to complete a weekly web-based questionnaire (Oslo Sports Trauma Research Center questionnaire on health problems) regarding their health problems.Results: A total of 70 athletes participated (37 male and 33 female athletes), with an average weekly response rate of 71%. The average weekly prevalence for all athletes was 27% (95%CI 17 to 38%) for all health problems, and 11% (95%CI 3 to 18%) for substantial health problems. Average prevalence varied significantly between endurance and explosive disciplines: a higher prevalence of all and substantial health problems and all and substantial overuse injuries was found in endurance disciplines. A higher prevalence of acute injuries was found in explosive disciplines. Characteristics of acute and overuse injuries differed according to sex and discipline: hamstring strain/cramps/spasms was the main injuries in explosive disciplines, and knee tendinopathy and lower leg strain/cramp/spasms in endurance disciplines, trunk cramps/spasms being frequent in both disciplines. Upper respiratory tract problems were the most commonly reported illnesses regardless of sex and disciplines.Conclusion: This study provides important information regarding the extent of health problem in Youth and Junior track and field athletes. This could help orient injury prevention measures. For injuries, it should be focused on muscle injuries, especially located on the hamstring, calf, and trunk. For illness, prevention measures could include: screening tests for airway problems, but also general illness prevention measures (e.g., drinking regularly, eating “safe” food, regular hand washing, decreasing contact with sick people, avoiding dehydration).

Relationship of isokinetic leg press strength with sprinting performance in junior elite volleyball players

Relationship of isokinetic leg press strength with sprinting performance in junior elite volleyball players

Alpine Ski Coaches' and Athletes' Perceptions of Factors Influencing Adaptation to Stress in the Classroom and on the Slopes.

Research examining the student-athlete experience proposes a number of factors that can be both sources of stress and/or support. The dual career pathway offers a number of potential positive outcomes including psychological, social, and financial benefits; however, challenges including time management, fatigue, and restricted social activities are well documented. In consideration of the multidimensional student-athlete experience and the numerous factors that influence the complexity of potential stress, a mixed methods research study design was used in the study. First, data collected from surveys completed by 173 elite junior alpine skiers were analyzed to identify the degree to which athletes report experiencing stress associated with specific aspects pertaining to training, life, and organizational factors. These factors were then explored through semi-structured interviews with six coaches at the associated national elite sport schools. Taken collectively, athletes’ reports of psychophysiological training stress on the Multidimensional Training Distress Scale were low. Scores on the college student-athletes’ life stress scale revealed very low levels of general life stress; although the subscales associated with “performance demand” and “academic requirements” scored marginally higher. Scores on the Organizational Stressor Indicator for Sport Performers indicated low levels of organizational stress. The interviews with coaches elucidated the underlying factors potentially influencing athletes’ positive adaptations to stress as they reported programming a number of strategies to reduce negative outcomes. Coaches aimed to teach athletes self-awareness and regulation strategies through the use of the training diaries and ongoing communication to promote positive adaptation to stress. A number of coaches also worked with sport psychology consultants to optimize athletes’ training and study situations. Traditionally, research has noted high levels of stress in student-athletes due to co-occurring demands (school & sport); however, the data in the present study suggests that optimizing support mechanisms across domains can promote positive adaptations to potential sources of stress.

A Case Study of Junior Elite Tennis Players' and their Parent’s Self-Talk

Automatic self-talk of elite athletes provides valuable insight into their emotional experience and self-regulation strategies in competition. To date, there is a shortage of research examining elite junior athletes’ automatic self-talk in competition through a qualitative lens. Despite parents’ key role in the well-being and performance of their child, there is no study about junior elite athletes’ and their parents’ self-talk during a competition. Hence, the aim of this study is to examine the content of elite junior tennis players’ automatic self-talk as well as the content of their parents’ self-talk regarding their emotions during important matches. In each of the two cases under investigation, individual in-depth interviews were conducted with a tennis player and his or her most dedicated parent. The results were analyzed using Yin’s (2014) multiple-case study strategy and Polkinghorne’s (1995) narration inquiry strategy. An analysis of automatic self-talk content was conducted individually for each case, followed by an intra-case and cross-case analysis. The results reveal that each player’s and parent’s automatic self-talk is related to their own subjective emotional experience during the matches. The findings highlight similarities in athletes’ and parents’ self-talk patterns, reflecting the potential influence of parents in athletes’ performance pressure and their goal-directed self-talk strategies. The differences observed between the self-talk of players and their parents demonstrate the relevance of examining their profiles to better understand the origin of individual differences in self-talk.

Anthropometric and Motor Performance Variables Are Decisive Factors for The Selection of Junior National Female Volleyball Players.

This study examined whether anthropometric and fitness tests might successfully predict selection of young female volleyball players for a junior national team. Sixty four female players (age: 14.4 ± 0.5 y, body height: 1.76 ± 0.05 m, body mass: 63.9 ± 6.4 kg) underwent a selection procedure for the junior national team. Anthropometric data and speed and power test results were obtained and players were graded for their performance in a volleyball tournament. Selected players differed from the non-qualified in body height (3.4%; p = 0.001), standing reach height (2.6%; p = 0.001), the sum of skinfolds (15.4%; p = 0.035), body mass index (BMI; 7.1%; p = 0.005) and spike jump and reach (SJR) (2.5%; p = 0.001). Selected players were classified in the 99.2 ± 1.6 percentile in body height and in the 51.4 ± 20.6 percentile in the BMI, which were significantly different from those of the non-qualified players (95.4 ± 7.0 and 66.7 ± 18.6, p = 0.02 and p = 0.004, respectively). Stepwise discriminant analysis yielded a discriminant function (p < 0.001, η2 = 0.78) that was highly loaded by height, SJR and the BMI (r = 0.79, r = 0.74 and r = -0.53, respectively). Cross validation results showed that selection was correctly predicted in 15 out of the 20 selected players (predictive accuracy: 75.0%) and in 35 out of the 44 non-qualified players (predictive accuracy: 79.5%). In conclusion, body height, the BMI and SJR height successfully discriminated between selected and non-qualified elite young female junior national team volleyball players. The equal vertical jump, sprint and agility of selected and non-qualified players, highlight the importance of body height and the BMI for selection of elite junior female volleyball players.

Measuring biomechanical loads and asymmetries in junior elite long-distance runners through triaxial inertial sensors

Summary Background Despite its various positive health effects, long-distance running implies substantial biomechanical loads on the musculoskeletal system, especially in a competitive context. The incidence of running-related overuse injuries is high, especially for the tibia being one of the predominant injury localisations. Tibial impact accelerations are an established valid proxy measure for impact forces and, as such, considered a more direct estimate of tibial bone load than ground reaction forces. Assessing individual tibial and upper-body impact accelerations may help balancing biomechanical loads during training for long-distance running and triathlon. Material and methods We employed inexpensive, wireless, lightweight, triaxial inertial measurement units (IMUs) as wearables for measuring tibial, sacral and scapular impact loads and asymmetries in 45 healthy junior-elite long-distance runners at submaximal running speeds. Moreover, we investigated the effects of ground surface vs. running speed on tibial load in 8 well-trained, healthy runners and triathletes. Results Mean peak tibial accelerations in junior elite long-distance runners ranged between 14 ± 3 and 16 ± 3 g (g ≈ 9.81 m s−1) for running speeds of 14–16 km h−1. Corresponding mean peak sacral and scapular accelerations amounted to 4 ± 1 g to 5 ± 1 g (32 ± 8% of tibial load) and 4 ± 1 g (27 ± 6%), respectively. Observed lateral asymmetries in tibial and scapular accelerations yielded mean absolute values of 9 ± 8% (95th percentile of 24%) and 9 ± 10% (32%). The effect of running speed on tibial accelerations was approximately twice as large as the effect of ground surface. Among asphalt, tartan, treadmill and turf, only turf induced a significantly lower tibial load in well-trained runners. Conclusions IMU sensors represent a promising tool for assessing biomechanical loads and asymmetries in running under field conditions. With the orientation values derived in this study, they may be used to reduce individual risks of overuse injuries and, in future, possibly to assess running efficiency. Level of evidence Ib.

CAM-type femoroacetabular impingement in male elite junior cross-country skiers and non-athlete controls: a cross-sectional MRI study

ObjectivesCross-country (CC) skiing consists of two main techniques: classic and skating. Hip motion during the skating technique is similar to that in ice skating and is considered a risk factor...

A Prospective Cohort Study of Load and Wellness (Sleep, Fatigue, Soreness, Stress, and Mood) in Elite Junior Australian Football Players.

To investigate associations between load (training and competition) and wellness in elite junior Australian Football players across 1 competitive season. A prospective cohort study was conducted during the 2014 playing season in 562 players from 9 teams. Players recorded their training and match intensities according to the session-rating-of-perceived-exertion (sRPE) method. Based on sRPE player loads, a number of load variables were quantified, including cumulative load and the change in load across different periods of time (including the acute-to-chronic load ratio). Wellness was quantified using a wellness index including sleep, fatigue, soreness, stress, and mood on a Likert scale from 1 to 5. Players spent an average of 85 (21)min in each match and 65 (31)min per training session. Average match loads were 637 (232)arbitrary units, and average training loads were 352 (233)arbitrary units. Over the 24 wk of the 2014 season, overall wellness had a significant linear negative association with 1-wk load (B = -0.152; 95% confidence interval, -0.261 to -0.043; P = .006) and an inverse U-curve relationship with session load (B = -0.078; 95% confidence interval, 0.143 to 0.014; P = .018). Mood, stress, and soreness were all found to have associations with load. This study demonstrates that load (within a session and across the week) is important in managing the wellness of elite junior Australian Football players. Quantifying loads and wellness at this level will help optimize player management and has the potential to reduce the risk of adverse events such as injury.

The Role of Perfectionism and Controlling Conditions in Norwegian Elite Junior Performers' Motivational Processes.

Conceptualized within the framework of self-determination theory, the aim of the current study was to investigate the relation between perfectionistic concerns and (a) controlled (non-self-determined) motivation and (b) performance anxiety through basic psychological need frustration (frustration of competence, autonomy, and realtedness), and if these relations would be moderated by controlling teaching/coaching conditions. We used a cross-sectional moderated mediation design and purposefully selected Norwegian elite junior performers (N = 171; mean age = 17.3; SD age = 0.94) from talent development schools, who completed an online questionnaire to report their perceptions of the study variables. Associations were examined using structural equation modeling. The results showed that perfectionistic concerns were positively associated with controlling conditions, basic needs frustration, controlled motivation, and performance anxiety. Reported controlling teaching/coaching conditions moderated the positive indirect relationship between perfectionistic concerns and (a) controlled motivation and (b) performance anxiety through competence need frustration. Specifically, these indirect associations were evident for performers reporting moderate or high levels of controlling teaching/coaching conditions. In contrast, there were no indirect associations via competence need frustration for those performers who reported low levels of controlling conditions. In conclusion, the results indicate that perfectionistic concerns appear to be a vulnerability factor that exposes elite junior performers to higher risks of entering a debilitative motivational process. This seems especially likely when exposed to controlling teaching/coaching conditions. Coaches and teachers working with elite junior performers should avoid using controlling mechanisms and instead foster autonomous functioning.

Career Performance Progressions of Junior and Senior Elite Track and Field Athletes

To compare and assess differences in the career performance progressions of elite junior and Olympic track and field athletes. Annual best performances from top 8 men and women (e.g. finalists) in track and field events at the 2000 World Junior Championships (junior cohort) and the 2000 Olympic Games (Olympic cohort) were examined. Annual bests of these finalists were tracked each year from select groups: sprints (100 m, 200 m), distance (1500 m, 5000 m), jumps (long jump, high jump), throws (discus, shot put). Age of best lifetime performance, age of final posted performance, and improvement from junior-age best to lifetime best performance were compared between groups. Olympic finalists achieved lifetime best performances at later ages than junior finalists [26.0 ± 4.0 years vs. 21.1 ± 3.5 years; age difference 90% CI (3.7–5.2 years), P < 0.001], and this significant age difference between cohorts was found within all four groups. Olympic finalists improved from under-20 best to lifetime best more so than junior finalists [6.1 ± 4.8% vs. 2.5 ± 2.3%; Age difference 90% CI (2.5–4.8%), P < 0.001]. Of 130 junior finalists, 54 did not improve after age 19, while 19 of 128 Olympic finalists posted no improvement after age 19. The data suggest that these two populations have different career performance progressions and challenge the notion that achieving elite success as a junior athlete is a prerequisite for the same success at the senior level.

Postural balance and rifle stability in a standing shooting position after specific physical effort in biathletes

ABSTRACTThe aim of the study was to evaluate the effect of maximal specific physical effort on postural balance and rifle stability in biathletes in a standing shooting position. The study included 10 junior elite biathletes. The measurements were taken with the Vicon system and AMTI force platform. Postural balance and rifle stability characteristics were determined at rest as well as 1 and 5 min post maximal specific physical effort which was performed on a ski ergometer and continued until exhaustion. Maximal physical effort exerted a significant effect on all examined postural sway and rifle sway characteristics. The duration of the post-exercise changes was longer than 5 minutes. Higher post-effort rifle sway was observed in the vertical direction than in the across the shooting line direction. Post-effort postural balance impairment in the shooting line was much greater than in the across the shooting line direction. Moreover, a strong correlation was found between postural balance and rifle stability. Maximal physical effort influenced postural balance and rifle stability during aiming. Rifle sway during aiming in a standing shooting position seems to be coordinated with the postural sway of the biathlete’s body. Thus, an increase in postural sway contributes to greater sway and lesser stability of the rifle.

Influence of Playing Standard on Upper- and Lower-Body Strength, Power, and Velocity Characteristics of Elite Rugby League Players.

Background: To compare load–velocity and load–power relationships among first grade (n = 26, age 22.9 ± 4.3 years), academy (n = 23, age 17.1 ± 1.0 years), and scholarship (n = 16, age 15.4 ± 0.5 years) Super League rugby league players. Methods: Participants completed assessments of maximal upper- and lower-body strength (1RM) and peak velocity and power at 20, 40, 60, and 80 kg during bench press and squat exercises, in a randomised order. Results: Bench press and squat 1RM were highest for first grade players compared with other standards (effect size (ES) = −0.43 to −3.18). Peak velocities during bench and squat were greater in the higher playing standards (ES = −0.39 to −3.72 range), except for the squat at 20 and 40 kg. Peak power was higher in the better playing standards for all loads and exercises. For all three groups, velocity was correlated to optimal bench press power (r = 0.514 to 0.766), but only 1RM was related to optimal power (r = 0.635) in the scholarship players. Only squat 1RM in the academy was related to optimal squat power (r = 0.505). Conclusions: Peak velocity and power are key physical qualities to be developed that enable progression from junior elite rugby league to first grade level. Resistance training should emphasise both maximal strength and velocity components, in order to optimise upper- and lower-body power in professional rugby league players.

The Prevalence of Musculoskeletal Injuries in Junior Elite Squash Players

Background: The dynamics and competitiveness of squash place a high demand on the musculoskeletal system of players, thus increasing the injury risk of youth squash players. Objectives: The purpose of this study was to analyze and report the musculoskeletal injury epidemiology of junior elite squash players. Methods: Twenty-one male adolescent squash players were included in this retrospective analysis of routinely collected data over a period of 6-years. Origin, location, diagnosis and incidence of all injuries are reported. Results: A total of 212 injuries were recorded: 58% of these injuries (n = 124) were squash (on-court) related, 16% (n = 33) were because of other training activities and 26% of these injuries were (n = 55) non-squash related. Most of squash related training injuries were in the lower limbs (67%, n = 105). The most frequently reported diagnosis was “osteochondrosis” (22%, n = 34), followed by “contusion” (13%, n = 20). Time-loss injuries accounted for 103 injuries and the overall injury incidence was 4.78 per 1000 hours of training. Conclusions: It was established that pre-mature squash players are at greater risk of growth related injuries during their peak growth period. A significant number of injuries at junior level are found to occur outside of training time and result in periods of time loss. As a result, skill acquisition is negatively affected which in turn negatively affects development opportunities in junior athletes.