Introduction: Although short-term (approximately 10-min) fatiguing DP has been reported not to alter the joint kinematics or displacement of centre mass (COM) high-level skiers, we hypothesize that prolonged does change these kinematics, since muscular strength is impaired following endurance events lasting longer than 2 h. Methods: During 58-km Marcialonga race in 2017, fastest 15 male skiers were videofilmed (100 fps, FHD resolution sagittal plane) on two 20-m sections (inclines: 0.7 ±...

The relative age effect (RAE; i.e., an asymmetry in the birth distribution) is a bias observed sport competitions that may favour relatively older athletes talent identification. Therefore, aim of this study was to investigate presence RAE elite soccer players competing Italian championships, even considering discriminations younger and Serie A (in relation median sample), different positional roles (i.e., goalkeeper, defender, midfielder, forward) for each category. total 2051 into...

This study aimed to evaluate youth-to-senior transition and the relative age effect in Italian female football national teams. Birthdate data of 774 players selected for Under 17 (N = 416), 19 265) National Senior team 93) were analysed. The rate was determined by number youth competing (and vice versa), whilst birth quarter (Q) distributions with a chi-square goodness-of-fit test. Only 17.4% able be team, whereas 31.2% reached high-senior level without being groups. Data revealed skewed...

Introduction The idea that early sport success can be detrimental for long-term performance is still under debate. Therefore, the aims of this study were to examine career trajectories Italian high and long jumpers provide a better understanding development in jumping events. Methods official long-jump high-jump rankings Track Field Federation collected from age 12 termination, both genders year 1994 2014. Top-level athletes identified as those with percentile their personal best between 97...

Many previous studies in national team sports did not report evidence about relative age effect (RAE) senior categories. This study aimed for the first time to determine if RAE may specifically affect early, but late, phase of career elite sports. A total 3,319 birthdates (basketball: n = 642; rugby: 572; soccer: 1318; volleyball: 337; water polo: 450) players were analyzed. Senior with an lower or equal 25° percentile considered as early while others late players. Separate Poisson...

Conflicting results have been reported on whether closed kinetic chain exercises (such as a leg press) may induce more balanced activation of vastus medialis (VM) and lateralis (VL) muscles compared with open exercise pure knee extension). This study aimed to 1) compare between-vasti motor unit activity 2) analyze the combined behavior from both between exercises. Thirteen participants (four women, mean ± SD age: 27 5 yr) performed isometric extension press at 10, 30, 50, 70% maximum...

ABSTRACT Introduction : We describe the innervation zone (IZ) location in 43 muscles to provide information for appropriate positioning of bipolar electrodes clinical and research applications. Methods The IZ was studied 40 subjects (20 men 20 women) using multichannel surface electromyography (sEMG). Signal quality checked visually identify motor unit action potentials estimate muscle fiber conduction velocity. Results 33 were classified as excellent or good, because it possible an area...

The aims of the study were to describe physiological profile a 65-km (4000-m cumulative elevation gain) running mountain ultra-marathon (MUM) and identify predictors MUM performance. Twenty-three amateur trail-runners performed anthropometric evaluations an uphill graded exercise test (GXT) for VO2max, ventilatory thresholds (VTs), power outputs (PMax, PVTs) heart rate response (HRmax, HR@VTs). Heart (HR) was monitored during race intensity expressed as: Zone I (<VT1), II (VT1-VT2), III...

Abstract A quantitative observational laboratory study was conducted to characterize and classify core training exercises executed in a suspension modality on the base of muscle activation. In prospective single-group repeated measures design, seventeen active male participants performed four typically associated with (roll-out, bodysaw, pike knee-tuck). Surface electromyographic signals were recorded from lower upper parts rectus abdominis, external oblique, internal erector spinae muscles...

The relative age effect (RAE) is a common phenomenon observed in youth sports and characterized by significant over-representation of athletes born close to the date selection. However, there lack research on RAE world-class track field it not clear if this persists into adulthood. Thus, study examined for first time prevalence magnitude at world class level all disciplines. Birthdates 39,590 (51.6% females) ranked International Association Athletics Federations top 100 official lists...

To quantify how many of the top 50 under-18 (U18) sprinters in world managed to become ranked as adult competitors. The authors also described career trajectory athletes during either U18 or senior category.A total 4924 male and female competing sprint races International Association Athletics Federations (now World Athletics) lists any seasons between 2000 2018 were included study. positions all-time U18, senior, both categories analyzed.Only 17% 21% athletes. consistently produced yearly...

Background and Objectives: Gait disorders represent one of the most disabling aspects in multiple sclerosis (MS) that strongly influence patient quality life. The improvement walking ability is a primary goal for rehabilitation treatment. aim this study to evaluate effectiveness robot-assisted gait training (RAGT) association with physiotherapy treatment patients affected by MS comparison ground conventional training. Study design: Randomized controlled crossover trial. Materials Methods:...

Football is a popular sport, but little known about the youth-to-senior transition rates in elite players, particularly large and successful countries. This study aims to investigate rate Italian national football team, both prospectively retrospectively, explore if Relative Age Effects (RAEs) affect this transition. Data from 885 players selected youth senior teams between 2000 2021 were included study. For each player, birthdate number of selection Under 16, 17, 19, 21 team was considered....

ABSTRACT We investigate the contribution of isometric rate torque development (RTD) and maximal voluntary (MVT) to dynamic force production capacities knee extensors obtained from torque–velocity (TV) relationship, that is, theoretical velocity ( V 0 ), T power P max ). Single‐leg were tested in 64 young adults (31 females). RTD root mean square (RMS) electromyographic signals recorded during incremental load (nonisokinetic) contractions. In test, continuously measured averaged over 80°–140°...

Over the past decade, linear and nonlinear surface electromyography (EMG) variables highlighting different components of fatigue have been developed. In this study, we tested fractal dimension (FD) conduction velocity (CV) rate changes as descriptors, respectively, motor unit synchronization peripheral manifestations fatigue. Sixteen elderly (69 ± 4 years) seventeen young (23 2 physically active men (almost 3–5 h physical activity per week) executed one knee extensor contraction at 70% a...

Due to poling action and upper body engagement, Nordic walking (NW) has additional health benefits with respect conventional walking. The aim of this study was evaluate the differences in muscle activation metabolic responses between NW, performed technique suggested by NW instructors, some modifications way move limb poles. Ten instructors volunteered walk on a treadmill at 5.5 km•h-1 five conditions: (W), (NW), weak (NWweak), straight-upper limbs moving shoulders (NWshoulder) elbow...

Muscle damage and repeated bout effect have been studied after pure eccentric-only exercise. The aim of this study was to evaluate muscle induced by enhanced eccentric squat exercise using flywheel device.Thirteen healthy males volunteered for study. Creatine kinase blood activity (CK), quadriceps isometric peak torque soreness were used as markers damage. dependent parameters measured at baseline, immediately each day up 96 hours the session. intervention consisted 100 repetitions device....

Nordic walking is a form of that includes poling action, and therefore an additional subtask, with respect to conventional walking. The aim this study was assess whether required task-specific muscle coordination We compared the electromyographic (EMG) activity 15 upper- lower-limb muscles 9 instructors, while executing at 1.3 ms-1 on treadmill. Non-negative matrix factorization method applied identify synergies, representing spatial temporal organization coordination. number synergies not...

This study aimed (a) to estimate the transition rate for top 50 ranked track and field jumpers, (b) compare performance progression of senior jumpers ( top50 ) those who failed be in category despite being under 18 only U18 ), (c) verify whether relative age effect may at least partially explain differences two above‐mentioned subgroups. The career trajectories 5981 athletes (2837 females) competing jump events from 2000 2019 were extracted World Athletics database. all‐time each 16 years...

Purpose : This study aimed to describe the career performance progression of elite early- and later-success international swimmers competing in sprint events (ie, 50 100 m). Methods The trajectories 6003 (50.9% females; 58,760 unique records) 4 swimming strokes were evaluated. Swimmers with early later success identified. authors identified top all-time junior who did not reach rankings their senior career, vice versa, successful both career. Results Early-success mainly achieved peak before...

This study investigated (1) the transition rate of elite world-class throwers, (2) age peak performance in either junior and/or senior athletes, and (3) if relative effect (RAE) influences chance being considered category.The career trajectories 5108 throwers (49.9% females) were extracted from World Athletics database. The authors identified who had reached level (operationally defined as all-time top 50 ranked for each category) category calculated junior-to-senior rate. RAE also...