Reliability and Sensitivity of Reaction Time Measurements During Quasi-Realistic Soccer Situations

Motor Control ◽  
2021 ◽  
pp. 1-11
Author(s):  
Lazar Tomic ◽  
Danica Janicijevic ◽  
Aleksandar Nedeljkovic ◽  
Bojan Leontijevic ◽  
Amador García-Ramos

Reliability and sensitivity of reaction time (RT) during quasi-realistic soccer situations was explored in 10 professional soccer players (skilled; age = 20.9 ± 3.6 years) and 10 males without soccer experience (nonskilled; age = 23.4 ± 0.5 years). The participants were instructed to react as fast as possible to a stimulus presented via the video-based method while standing on force platforms. RT was computed as the difference between the instant when the rate of force development of any leg reaches 5% of its maximal value and the instant of stimulus presentation. The results revealed acceptable to high reliability of RT (intraclass correlation coefficient median = .90; coefficient of variation ≤ 5.83%), and shorter RT for skilled compared with nonskilled participants in three out of eight comparisons (effect size range = 1.00–1.41). The video-based methods can be confidently used to assess the RT in soccer players.

2016 ◽  
Vol 28 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Susana C. A. Póvoas ◽  
Carlo Castagna ◽  
José Manuel da Costa Soares ◽  
Pedro Silva ◽  
Manuel Coelho-e-Silva ◽  
...  

Purpose:The reliability and construct validity of three age-adapted-intensity Yo-Yo tests were evaluated in untrained (n = 67) vs. soccer-trained (n = 65) 9- to 16-year-old schoolgirls.Methods:Tests were performed 7 days apart for reliability (9- to 11-year-old: Yo-Yo intermittent recovery level 1 children’s test; 12- to 13-yearold: Yo-Yo intermittent endurance level 1; and 14- to 16-year-old: Yo-Yo intermittent endurance level 2).Results:Yo-Yo distance covered was 40% (776 ± 324 vs. 556 ± 156 m), 85% (1252 ± 484 vs. 675 ± 252 m) and 138% (674 ± 336 vs. 283 ± 66 m) greater (p ≤ .010) for the soccer-trained than for the untrained girls aged 9–11, 12–13 and 14–16 years, respectively. Typical errors of measurement for Yo-Yo distance covered, expressed as a percentage of the coefficient of variation (confidence limits), were 10.1% (8.1–13.7%), 11.0% (8.6–15.4%) and 11.6% (9.2–16.1%) for soccer players, and 11.5% (9.1–15.8%), 14.1% (11.0–19.8%) and 10.6% (8.5–14.2%) for untrained girls, aged 9–11, 12–13 and 14–16, respectively. Intraclass correlation coefficient values for test-retest were excellent (0.795–0.973) in both groups. No significant differences were observed in relative exercise peak heart rate (%HRpeak) between groups during test and retest.Conclusion:The Yo-Yo tests are reliable for determining intermittent-exercise capacity and %HRpeak for soccer players and untrained 9- to 16-year-old girls. They also possess construct validity with better performances for soccer players compared with untrained age-matched girls, despite similar %HRpeak.


Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 577 ◽  
Author(s):  
Shunrou Fujiwara ◽  
Shinpei Sato ◽  
Atsushi Sugawara ◽  
Yasumasa Nishikawa ◽  
Takahiro Koji ◽  
...  

The aim of this study was to investigate whether variation in gait-related parameters among healthy participants could help detect gait abnormalities. In total, 36 participants (21 men, 15 women; mean age, 35.7 ± 9.9 years) performed a 10-m walk six times while wearing a tri-axial accelerometer fixed at the L3 level. A second walk was performed ≥1 month after the first (mean interval, 49.6 ± 7.6 days). From each 10-m data set, the following nine gait-related parameters were automatically calculated: assessment time, number of steps, stride time, cadence, ground force reaction, step time, coefficient of variation (CV) of step time, velocity, and step length. Six repeated measurement values were averaged for each gait parameter. In addition, for each gait parameter, the difference between the first and second assessments was statistically examined, and the intraclass correlation coefficient (ICC) was calculated with the level of significance set at p < 0.05. Only the CV of step time showed a significant difference between the first and second assessments (p = 0.0188). The CV of step time also showed the lowest ICC, at <0.50 (0.425), among all parameters. Test–retest results of gait assessment using a tri-axial accelerometer showed sufficient reproducibility in terms of the clinical evaluation of all parameters except the CV of step time.


2020 ◽  
Vol 15 (7) ◽  
pp. 1012-1018
Author(s):  
Guillaume Levernier ◽  
Pierre Samozino ◽  
Guillaume Laffaye

Purpose: To compare the force-production capacities among boulderers, lead climbers, and speed climbers during a pull-up test using a force–velocity–power profile. Methods: In total, 24 high-elite climbers (11 boulderers, 8 lead climbers, and 5 speed climbers) did 2 pull-ups at different percentages of their body mass (0%, 30%, 45%, 60%, and 70%). Force–velocity–power profile analyses were performed with the use of an accelerometer for each load. The intraclass correlation and coefficients of variation were calculated. A 1-way analysis of variance was performed with a Tukey post hoc test to assess the difference between the groups. Results: Regarding force, the coefficient of variation ranged from 1.00% to 6.18% and the intraclass correlation ranged from .98 to .99. For velocity, the coefficient of variation ranged from 2.75% to 6.62% and the intraclass correlation ranged from .84 to .95. The linear regression slope showed R2 to be between .93 and .99, confirming the high quality of the linear relationship between velocity and the external force produced during a pull-up. Boulderers presented significantly higher (P < .05) maximal power (+22.30% and +26.29%), mean power for the pull-up at body weight (+23.49% and +25.35%), and theoretical maximal velocity at zero force (+23.92% and +21.53%) than lead and speed climbers and a more significant curve increase (+35.21% compared with lead climbers). Conclusions: The reliability of the method was shown to be high. Moreover, boulderers were able to develop an important external force and had the capacity to maintain high speed when force production increased.


2018 ◽  
Vol 13 (5) ◽  
pp. 562-567 ◽  
Author(s):  
Mohamed S. Fessi ◽  
Fayçal Farhat ◽  
Alexandre Dellal ◽  
James J. Malone ◽  
Wassim Moalla

Purpose: To investigate the difference between straight-line (STL) and change-of-direction (COD) intermittent-running exercises in soccer players. Methods: Seventeen male professional soccer players performed the agility T test and 6 intermittent-running exercises: 10 s at 130% of maximal aerobic speed (MAS) alternated with 10 s of rest (10-10), 15 s at 120% of MAS alternated with 15 s of rest (15-15), and 30 s at 110% of MAS alternated with 30 s of rest (30-30) both in STL and with COD. All exercises were monitored using a global positioning system. Heart rate was measured during exercises, and rating of perceived exertion (RPE) was collected postexercise. The difference (Δ) between covered distance in STL and COD exercises at a similar load was calculated, and relationships between T test and Δ distance were analyzed. Results: COD intermittent exercises showed a significantly decreased distance covered and an increase in the number of accelerations, peak heart rate, and RPE compared with STL intermittent exercises at a similar load. High relationships were observed between T-test performance and Δ distance in 10-10 (r = .72, P < .01) and 15-15 (r = .77, P < .01), whereas no significant relationships were observed between T-test performance and Δ distance in 30-30 (r = −.37, P = .2). Conclusion: Intermittent COD exercises were associated with higher acceleration, peak heart rate, and RPE than STL during 10-10 and 15-15 exercises. The ability to rapidly change direction is crucial to perform intense sport-specific running in professional soccer players.


2020 ◽  
Vol 72 (1) ◽  
pp. 265-278
Author(s):  
Rodrigo F. Morandi ◽  
Eduardo M. Pimenta ◽  
André G. P. Andrade ◽  
Tane K. F. Serpa ◽  
Eduardo M. Penna ◽  
...  

AbstractWe aimed to create a single subjective method to assess both internal training loads and subsequent fatigue. This new training-fatigue (dose-response) scale (TFS) was composed of two similar scales with the same properties, metrics and construction criteria. These two scales were designed to rate the perceived exertion (RPETFS) and perceived fatigue (RPFTFS) in professional soccer players. Twenty-two athletes participated to establish reliability, and 15 participated to establish validity. For reliability, the intraclass correlation coefficient (ICC) and standard error of measurement (SEM) were used. For criterion validity, the Spearman’s correlation coefficient and linear regression analyses were applied. Associations between RPETFS and RPFTFS were verified by a chi square test, and a further factorial exploratory analysis was conducted. RPETFS and RPFTFS were found to be reliable (ICC 0.74 and 0.77, SEM 0.30 and 0.30, respectively) and valid. RPETFS was best explained by the internal load of the Banister training impulse (p < 0.001), while RPFTFS was best explained by the internal load of the Stagno training impulse (p < 0.001). An association was found between the scales (RPETFS and RPFTFS) in which training duration had a more substantial impact on these subjective perceptions than did training intensity (p < 0.01). RPETFS and RPFTFS scales are reliable and valid for monitoring training sessions in Brazilian professional soccer players. The simultaneous oscillations of the RPETFS and RPFTFS scores can be used by staff members to better plan weekly training programs based on dose-response ratings. Finally, training duration must be carefully controlled because it has a greater impact than intensity on subjective perceptions.


2021 ◽  
Vol 21 (4) ◽  
pp. 337-342
Author(s):  
Giacomo Cofano ◽  
Francesca D’Elia ◽  
Andrea Piccinno ◽  
Italo Sannicandro

The study purpose. The purpose of the study is to analyze and understand the internal and external load in Large Sided Games (LSG) exercises carried out on fields of different sizes, defined as Small – Large Sided Games (SLSG) and Big – Large Sided Games (BLSG), according to the different square meters assigned to each player.  Materials and methods. 22 professional soccer players (average age: 23.59 ± 4.87 years, weight: 77.8 ± 7.6 kg, height: 183.5 ± 7.5 cm, age training: 13.1 ± 1.7). The LSG exercises were carried out on a 60 x 54 m field (270 m2/player), defined as "small" (SLSG) and on a 65 x 60 m field (325 m2/player) defined as "big" (BLSG). During the two LSG exercises, the internal load and the external load were analyzed. LSG exercises were performed with 4 sets of 5 minutes each, with 2 minutes of passive recovery between each set.  Results. The results of the internal load analysis show how the LSG carried out on a SLSG field provides higher and more significant HR values (p < 0.0005) than those emerged during the exercise carried out on a BLSG field. The RPE value is also higher during the SLSG, although statistically no significant difference appears. The analysis of the external load in relation with the observed parameters shows higher values in the BLSG, except for the number of accelerations. Conclusions. In terms of external and internal load, the results of this study showed how the difference of 55 m2/player can radically change the configuration of the two exercises. These differences allow to use both dimensions within a micro-cycle, but in sessions with different goals. The most appropriate sessions for LSGs are the first post-match session in which the rest day is not gone and the fourth session 3 days before the match.


2018 ◽  
Vol 24 (6) ◽  
pp. 432-435
Author(s):  
Fabiano de Barros Souza ◽  
Ricardo Cesar Alves Ferreira ◽  
Wendel Simoes Fernandes ◽  
Wellington Ribeiro ◽  
Rodrigo Alexis Lazo-Osorio

ABSTRACT Introduction: Ergospirometry is a noninvasive procedure used to assess physical performance or the capacity of an individual, through an analysis of expired gases and respiratory variables. This procedure is crucially important in sports, and makes a significant contribution to the measurement of cardiorespiratory fitness indices, such as maximal oxygen consumption (VO2 max) and the anaerobic threshold (AT). Objective: To assess aerobic capacity and potency in professional and junior soccer players, handball athletes, and women soccer players. Methods: Forty-eight athletes participated voluntarily and were divided into 4 groups. The first group consisted of 12 youth soccer players in the under-20 category, the second group was made up of 12 professional soccer players, the third group was made up of female soccer players, and the fourth group consisted of handball players. Results: We analyzed values such as peak VO2, average speed and heart rate at the anaerobic threshold as well as pulmonary ventilation. We found that the values were always greater for the group formed by professional soccer players, with the exception of mean maximum O2 consumption, in which the difference between this group and that of soccer players in the junior category was not significant. In other physical valences, there was a degree of similarity between the other groups, with special emphasis on pulmonary ventilation, which was significantly lower in the group of female soccer players. Conclusion: The particularities of each sport, such as pitch dimensions, duration, and tactical system, together with the morphology and sex of the athletes, directly influence peak VO2, AT and VE values in athletes who play different sports. Level of Evidence III; Development of diagnostic criteria in consecutive patients (with gold reference standard applied).


2017 ◽  
Vol 58 (1) ◽  
pp. 215-224 ◽  
Author(s):  
Yassine Negra ◽  
Helmi Chaabene ◽  
Samiha Amara ◽  
Slobodan Jaric ◽  
Mehréz Hammami ◽  
...  

Abstract Change of direction ability is an essential pre-requisite in team sports athletes. The Illinois change of direction test has been routinely used for testing change of direction ability in soccer players. The aim of the present study was to evaluate the Illinois change of direction test in young elite soccer players in terms of its reliability, usefulness and relationship with body size. A total of one hundred and ninety-four male, national-level soccer players were recruited. They were classified into four age groups (U-8, U-10, U-12 and U-14). Participants were tested using the Illinois change of direction test twice, and basic indices of body size were obtained. The Illinois change of direction scores showed high relative and absolute reliability in all age groups (all intraclass correlation coefficients were >0.91, and the standard error of measurement was <5%). The usefulness analysis showed that the Illinois change of direction test could detect small changes in performance in the U-10 and U-12 groups. However, it could only detect moderate changes in performance in the U-8 and U-14 groups. Although the Illinois change of direction test detected significant performance differences among groups, scores were not significantly related to body size (-0.30<r<0.15; p > 0.05). Taking into account the test’s high reliability and the appropriate level of usefulness, these results might support the use of the Illinois change of direction test as a standard measure for quantifying change of direction ability in young soccer players.


2020 ◽  
Vol 9 (9) ◽  
pp. 2728 ◽  
Author(s):  
Seo-Hyun Park ◽  
Soo-Hwan Byun ◽  
So-Hee Oh ◽  
Hye-Lim Lee ◽  
Ju-Won Kim ◽  
...  

The advantages of intraoral model scanning have yielded recent developments. However, few studies have explored the orthodontic clinical use of this technique particularly among young patients. This study aimed to evaluate the reliability, reproducibility and validity of the orthodontic measurements: tooth width, arch length and arch length discrepancy in each digital model obtained by model scanner and intraoral scanner, relative to a plaster model. Arch length measured using two methods: curved arch length (CAL) measured automatically by digital program and sum of sectional liner arch length (SLAL) measured sum of anterior and posterior liner arch lengths. Arch length discrepancy calculated each arch length measurement methods: curved arch length discrepancy (CALD) and sum of sectional liner arch length discrepancy (SLALD). Forty young patients were eligible for the study. A plaster model (P), model-scanned digital model (MSD) and intraoral scanned digital model (ISD) were acquired from each patient. The reliability of the measurements was evaluated using Pearson’s correlation coefficient, while the reproducibility was evaluated using the intraclass correlation coefficient. The validity was assessed by a paired t-test. All measurements measured in P, MSD and ISD exhibited good reliability and reproducibility. Most orthodontic measurements despite of CAL in MSD exhibited high validity. Only the SLAL and SLALD in ISD group differed significantly, despite the good validity of the tooth width, CAL and CALD. The measurements based on the digital program appeared high reliability, reproducibility and accurate than conventional measurement. However, SLAL and SLALD in ISD group appeared shorter because of distortion during intraoral scanning. However, this could be compensated by using digital programed curved arch. Although the validity of SLAL and SLALD in the ISD group differed statistically, the difference is not considered clinically significant. Although MSD and ISD are acceptable for a clinical space analysis, clinicians should be aware of digital model-induced errors.


2021 ◽  
Vol 7 (4) ◽  
pp. 8-18
Author(s):  
A. Kukrić ◽  
M. Joksimović ◽  
B. Petrović ◽  
F. Latino ◽  
R. Pavlović ◽  
...  

Purpose: The aim of the study was to determine the differences between football players and basketball players in the mean absolute values ​​of maximum torque flexors and extensors, ratio of maximum hamstring torque to maximum quadriceps torque dominant (DOM) non-dominant (ND) leg and differences in bilateral imbalance of flexor muscles and knee extensors. Material and methods: The research included a sample of 39 professional athletes. The first subsample included 19 professional basketball players while the second subsample included 20 professional soccer players. Results: Based on the results of the torques of the extensors in the knee joint of the DOM and ND legs, it was established that there is no statistically significant difference between basketball players and football players. However, a statistically significant difference was found in the torque flexors of the knee joint DOM (p≤0.01) and ND (p≤0.00) of the leg between basketball players and football players. On the other hand, the results of the research indicate that the difference between basketball players and football players in the ratio of Hamstrings peak torque to Quadriceps peak torque was recorded only in the ND leg (p≤0.02), while the difference in the DOM leg is not statistically significant. The results of our study indicate that basketball players have a higher percentage of imbalances compared to football players, especially in m. hamstrings. Conclusion: This study provides normative data on populations specific to soccer and basketball, but does not provide evidence of the ability of the isokinetic assessment of lower extremity muscle strength to predict injuries to football players and basketball players.


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