scholarly journals A Novel Method of Assessment for Monitoring Neuromuscular Fatigue in Australian Rules Football Players

2019 ◽  
Vol 14 (5) ◽  
pp. 598-605 ◽  
Author(s):  
Joel Garrett ◽  
Stuart R. Graham ◽  
Roger G. Eston ◽  
Darren J. Burgess ◽  
Lachlan J. Garrett ◽  
...  
Keyword(s):  
High Performance ◽  
Recovery Phase ◽  
Neuromuscular Fatigue ◽  
Football Players ◽  
Alternative Method ◽  
Jump Test ◽  
Australian Rules Football ◽  
Novel Method ◽  
Run Test ◽  
Method Of Assessment

Purpose: To compare the sensitivity of a submaximal run test (SRT) with a countermovement-jump test (CMJ) to provide an alternative method of measuring neuromuscular fatigue (NMF) in high-performance sport. Methods: A total of 23 professional and semiprofessional Australian rules football players performed an SRT and CMJ test prematch and 48 and 96 h postmatch. Variables from accelerometers recorded during the SRT were player load 1D up (vertical vector), player load 1D side (mediolateral vector), and player load 1D forward (anteroposterior vector). Meaningful difference was examined through magnitude-based inferences (effect size [ES]), with reliability assessed as typical error of measurements expressed as coefficient of variance. Results: A small decrease in CMJ height, ES −0.43 ± 0.39 (likely), was observed 48 h postmatch before returning to baseline 96 h postmatch. This was accompanied by corresponding moderate decreases in the SRT variables player load 1D up, ES −0.60 ± 0.51 (likely), and player load 1D side, ES −0.74 ± 0.57 (likely), 48 h postmatch before also returning to prematch baseline. Conclusion: The results suggest that in the presence of NMF, players use an alternative running profile to produce the same external output (ie, time). This indicates that changes in accelerometer variables during an SRT can be used as an alternative method of measuring NMF in high-performance Australian rules football and provides a flexible option for monitoring changes in the recovery phase postmatch.

scholarly journals Comparison of a Countermovement Jump Test and Submaximal Run Test to Quantify the Sensitivity for Detecting Practically Important Changes Within High-Performance Australian Rules Football

2020 ◽  
Vol 15 (1) ◽  
pp. 68-72
Author(s):  
Joel M. Garrett ◽  
Stuart R. Graham ◽  
Roger G. Eston ◽  
Darren J. Burgess ◽  
Lachlan J. Garrett ◽  
...  
Keyword(s):  
High Performance ◽  
Football Players ◽  
Countermovement Jump ◽  
Good Reliability ◽  
Jump Test ◽  
Australian Rules Football ◽  
The Difference ◽  
Test Retest Reliability ◽  
Run Test ◽  
Difference Effect

Purpose: To determine the typical variation of variables from a countermovement jump (CMJ) test and a submaximal run test (SRT), along with comparing the sensitivity of each test for the detection of practically important changes within high-performance Australian rules football players. Methods: A total of 23 professional and semiprofessional Australian rules football players performed 6 CMJs and three 8-second 50-m runs every 30 seconds (SRT), 7 days apart. Absolute and trial-to-trial reliability was represented as a coefficient of variation, CV (±90% confidence intervals). Test–retest reliability was examined using the magnitude of the difference (effect size [±90% confidence interval]) from week 1 to week 2. The smallest worthwhile change was calculated as 0.25 × SD. Results: Good reliability (CVs = 6.6%–9.3%) was determined for all variables except eccentric displacement (CV = 12.8%), with no clear changes observed in any variables between week 1 and week 2. All variables from the SRT possessed a CV less than smallest worthwhile change, indicating an ability to detect practically important changes in performance. Only peak velocity from the CMJ test possessed a CV less than smallest worthwhile change, exhibiting a limitation of this test in detecting practically meaningful changes within this environment. Conclusions: The results suggest that while all variables possess acceptable reliability, a SRT might offer to be a more sensitive monitoring tool than a CMJ test within high-performance Australian rules football, due to its greater ability for detecting practically important changes in performance.

scholarly journals NORMATIVE BASIS FOR EVALUATION OF COORDINATION ABILITIES OF 9-10 YEAR OLD PUPILS

2019 ◽  
Vol 32 (4) ◽  
pp. 411-416
Author(s):  
Nikolina M. Tankusheva
Keyword(s):  
Primary Schools ◽  
High Performance ◽  
Third Grade ◽  
Motor Abilities ◽  
Jump Test ◽  
The Status ◽  
Long Jump ◽  
Normative Basis ◽  
Primary School Age ◽  
Run Test

Motor abilities, including coordination abilities, represent fundamental prerequisite for future high performance in the field of physical education and sport. In primary school age the foundation is laid for further development of coordination abilities, as well as to acquire knowledge, skills and habits to practice coordination exercises. This 9-10 years old period is called the "golden age" in relation with the pace of development of these abilities.The aim of this research is to establish the actual status of the coordination abilities of the third grade pupils in Bulgaria and draw up a normative table for control and evaluation on its basis. 1073 children, at the age of 9 and 10 years, including 564 boys and 509 girls in third grade, from 13 Bulgarian primary schools have been tested, using the test battery of Hirtz et al. (1985): Тest 1: Backwards ball throw at a target; Test 2: Long jump test (1 м); Test 3: Orientation shuttle run test aiming at numbered targets. To evaluate the status of each of the indicators examined the so-called Six Sigma method was applied and a normative table for the coordination abilities was developed, respectively for boys and girls. The average level of the pupils who participated in the test responds to rating 4.0

scholarly journals Pengaruh Lari Zig Zag dan Side Jump Sprint terhadap Peningkatan Power Pemain Sepak Bola

2020 ◽  
Vol 13 (2) ◽  
pp. 75-84
Author(s):  
Zulfikar H Wada ◽  
Mufa Wibowo
Keyword(s):  
Muscle Power ◽  
Vertical Jump ◽  
Intervention Group ◽  
T Test ◽  
American Football ◽  
Football Players ◽  
Jump Test ◽  
Australian Rules Football ◽  
Leg Muscle ◽  
Leg Muscle Power

Abstrak. Prevalensi terjadinya penurunan power pada otot hamstring menurut American football > 41%, sedangkan di Australian Rules Football terjadi penurunan power hamstring dengan presentase 16% yang angka kejadiannya pada urutan ketiga setelah cedera lutut dan ankle, oleh karena  itu perluya peningkatan power otot tungkai karena mempunyai pengaruh yang sangat penting terhadap performa tim untuk mencapai prestasi sepak bola yang lebih baik. Tujuan penelitian  untuk mengetahui perbedaan pengaruh lari zig zag dengan side jump sprint  terhadap peningkatan power otot tungkai pada pemain sepak bola. Metode penelitian menggunakan desain quasi eksperimental. Sampelnya yaitu Pemain bola di lapangan Nogotirto Yogyakarta yang berusia 17-22 tahun, pengambilan sampel dengan tehnik total sampling, dengan kriteria inklusi dan eksklusi didapatkan 16 orang dan dibagi 2 kelompok sehingga masing-masing 8 orang. Kelompok intervensi 1 dengan lari zig zag dan kelompok intervensi II dengan side jump sprint yang dilakukan selama 4 minggu dengan frekuensi latihan 3 kali seminggu,kemudian diukur dengan vertical jump test. Hasil Uji Paired Sample T-test pada hipotesis I dan II diperoleh nilai p :0,000 (p< 0,05), dan uji beda menggunakan Indevendent Sample T-test diperoleh nilai p :0,633 (p> 0,005). Dapat disimpulkan Tidak ada perbedaan pengaruh latihan lari zig zag dengan latihan side jump sprint terhadap peningkatan power otot tungkai pada pemain sepak bola.  Kata Kunci      : power, zig zag run, side jump sprint, vertical jump  The Influence of Zig Zag Running and Side Jump Sprint on Increasing the Power of Football Players   Abstract. The prevalence of decreasing power in the hamstring muscles according to American football> 41%, while in Australian Rules Football there is a decrease in power hamstring with a percentage of 16% which occurs in third place after knee and ankle injuries, therefore the need to increase leg muscle power because it has a very important influence on team performance to achieve better football performance. The purpose of this study was to determine the differences in the effect of zig zag running with side jump sprint on increasing leg muscle power in football players. The research method use quasi experimental design. The sample is football players in Yogyakarta Nogotirto field aged 17-22 years, taking the sampling with total sampling techniques, with inclusion and exclusion criteria found 16 people and divided into 2 groups so that each 8 people. Intervention group 1 with zig zag running and intervention group II with side jump sprint conducted for 4 weeks with exercise frequency 3 times a week, then measured by vertical jump test. The results of the Paired Sample T-test in hypotheses I and II obtained p values: 0,000 (p <0.05), and different tests using the Independent Sample T test obtained p values: 0.633 (p> 0.005). It can be concluded that there is no difference in the effect of zig zag running exercises with side jump sprint exercises on increasing leg muscle power in football players.   Keywords: power, zig zag run, side jump sprint, vertical jumps

scholarly journals A novel approach to the computation of one-loop three- and four-point functions: I. The real mass case

2019 ◽  
Vol 2019 (11) ◽  
Author(s):  
J Ph Guillet ◽  
E Pilon ◽  
Y Shimizu ◽  
M S Zidi
Keyword(s):  
Building Blocks ◽  
The Real ◽  
Alternative Method ◽  
Novel Approach ◽  
Reduction Methods ◽  
Real Mass ◽  
Novel Method ◽  
Algebraic Reduction ◽  
The One ◽  
Mass Case

Abstract This article is the first of a series of three presenting an alternative method of computing the one-loop scalar integrals. This novel method enjoys a couple of interesting features as compared with the method closely following ’t Hooft and Veltman adopted previously. It directly proceeds in terms of the quantities driving algebraic reduction methods. It applies to the three-point functions and, in a similar way, to the four-point functions. It also extends to complex masses without much complication. Lastly, it extends to kinematics more general than that of the physical, e.g., collider processes relevant at one loop. This last feature may be useful when considering the application of this method beyond one loop using generalized one-loop integrals as building blocks.

Influence of Neuromuscular Fatigue on Accelerometer Load in Elite Australian Football Players

2013 ◽  
Vol 8 (4) ◽  
pp. 373-378 ◽  
Author(s):  
Stuart J. Cormack ◽  
Mitchell G. Mooney ◽  
Will Morgan ◽  
Michael R. McGuigan
Keyword(s):  
High Speed ◽  
Neuromuscular Fatigue ◽  
Football Players ◽  
Countermovement Jump ◽  
Baseline Measure ◽  
Running Activity ◽  
Australian Football ◽  
Percent Contribution ◽  
Playing Time ◽  
The Impact

Purpose:To determine the impact of neuromuscular fatigue (NMF) assessed from variables obtained during a countermovement jump on exercise intensity measured with triaxial accelerometers (load per minute [LPM]) and the association between LPM and measures of running activity in elite Australian Football.Methods:Seventeen elite Australian Football players performed the Yo-Yo Intermittent Recovery Test level 2 (Yo-Yo IR2) and provided a baseline measure of NMF (flight time:contraction time [FT:CT]) from a countermovement jump before the season. Weekly samples of FT:CT, coaches’ rating of performance (votes), LPM, and percent contribution of the 3 vectors from the accelerometers in addition to high-speed-running meters per minute at >15 km/h and total distance relative to playing time (m/min) from matches were collected. Samples were divided into fatigued and nonfatigued groups based on reductions in FT:CT. Percent contributions of vectors to LPM were assessed to determine the likelihood of a meaningful difference between fatigued and nonfatigued groups. Pearson correlations were calculated to determine relationships between accelerometer vectors and running variables, votes, and Yo-Yo IR2 score.Results:Fatigue reduced the contribution of the vertical vector by (mean ± 90% CI) –5.8% ± 6.1% (86% likely) and the number of practically important correlations.Conclusions:NMF affects the contribution of individual vectors to total LPM, with a likely tendency toward more running at low speed and less acceleration. Fatigue appears to limit the influence of the aerobic and anaerobic qualities assessed via the Yo-Yo IR2 test on LPM and seems implicated in pacing.

scholarly journals The Effect of String Tension Variation on the Perceived Pitch of a Classical Guitar

2014 ◽  
Vol 2 (1) ◽  
pp. 53-81
Author(s):  
Wanda Jadwiga Lewis ◽  
James Raphael Smith ◽  
Wanda J. Lewis ◽  
James R. Smith
Keyword(s):  
Classical Theory ◽  
Fundamental Mode ◽  
String Tension ◽  
Classical Guitar ◽  
Sound Waves ◽  
Single Wave ◽  
Geometric Stiffness ◽  
Vibrating String ◽  
Novel Method ◽  
Method Of Assessment

Actual motion of a vibrating guitar string is a superposition of many possible shapes (modes) in which it could vibrate. Each of these modes has a corresponding frequency, and the lowest frequency is associated with a shape idealised as a single wave, referred to as the fundamental mode. The other contributing modes, each with their own progressively higher frequency, are referred to as overtones, or harmonics. By attaching a string to a medium (a soundboard) capable of a response to the vibrating string, sound waves are generated. The sound heard is dominated by the fundamental mode, ‘coloured’ by contributions from the overtones, as explained by the classical theory of vibration. The classical theory, however, assumes that the string tension remains constant during vibration, and this cannot be strictly true; when considering just the fundamental mode, string tension will reach two maximum changes, as it oscillates up and down. These changes, occurring twice during the fundamental period match the frequency of the octave higher, 1st overtone. It is therefore plausible to think that the changing tension effect, through increased force on the bridge and, therefore, greater soundboard deflection, could be amplifying the colouring effect of (at least) the 1st overtone.In this paper, we examine the possible influence of string tension variation on tonal response of a classical guitar. We use a perturbation model based on the classical result for a string in general vibration in conjunction with a novel method of assessment of plucking force that incorporates the engineering concept of geometric stiffness, to assess the magnitude of the normal force exerted by the string on the bridge. The results of our model show that the effect of tension variation is significantly smaller than that due to the installed initial static tension, and affects predominantly the force contribution arising from the fundamental mode. We, therefore, conclude that string tension variation does not contribute significantly to tonal response. Photo credit: By Biblola (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

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