scholarly journals The Effects of a Soccer-Specific Fitness Test on Eccentric Knee Flexor Strength

2020 ◽  
pp. 1-5
Author(s):  
Christopher Michael Brogden ◽  
Lewis Gough ◽  
Adam Kelly

Context: Physiological fitness testing, such as the Yo-Yo Intermittent Recovery Test (YYIR) is a key requirement of the Elite Player Performance Plan, introduced by the English Premier League. Eccentric hamstring strength has been identified as a risk factor for hamstring injuries in soccer players, with fatigue highlighted to further exasperate this issue. Objective: The aim of the current study was to examine the effect of the YYIR level 1 (YYIR1) on eccentric knee flexor strength assessed using the NordBord in youth soccer players. Design: Experimental design. Setting: Soccer club academy. Participants: A total of 67 male academy soccer players (age = 16.58 [0.57] y; height = 175.45 [5.85] cm; mass = 66.30 [8.21] kg) volunteered to participate in the current study during the English competitive soccer season. Main Outcome Measures: Participants conducted eccentric hamstring strength assessments using the NordBord prior to and immediately postcompletion of the YYIR1, with outcome measures of peak force and peak force relative to body mass recorded. Results: Paired t tests highlighted increased absolute eccentric knee flexor strength values (P < .001) immediately post-YYIR1 for both the dominant and nondominant limbs, with the same trend (P < .001) observed for eccentric strength relative to body mass. Conclusions: The results of this study indicate that the YYIR1 does not induce eccentric knee flexor fatigue and as such is not a valid assessment method to assess the effects of fatigue on hamstring function. However, results do suggest that the NordBord may be considered a viable and more accessible alternative to detect pre–post fitness test/fatigue protocol differences in eccentric knee flexor peak strength while working in the field.

2016 ◽  
Vol 11 (6) ◽  
pp. 721-726 ◽  
Author(s):  
Martin Buchheit ◽  
Yannick Cholley ◽  
Mark Nagel ◽  
Nicholas Poulos

Purpose:To examine the effect of body mass (BM) on eccentric knee-flexor strength using the Nordbord and offer simple guidelines to control for the effect of BM on knee-flexor strength.Methods:Data from 81 soccer players (U17, U19, U21, senior 4th French division, and professionals) and 41 Australian Football League (AFL) players were used for analysis. They all performed 1 set of 3 maximal repetitions of the bilateral Nordic hamstring exercise, with the greatest strength measure used for analysis. The main regression equation obtained from the overall sample was used to predict eccentric knee-flexor strength from a given BM (moderate TEE, 22%). Individual deviations from the BM-predicted score were used as a BM-free index of eccentric knee- flexor strength.Results:There was a large (r = .55, 90% confidence limits .42;.64) correlation between eccentric knee-flexor strength and BM. Heavier and older players (professionals, 4th French division, and AFL) outperformed their lighter and younger (U17–U21) counterparts, with the soccer professionals presenting the highest absolute strength. Professional soccer players were the only ones to show strength values likely slightly greater than those expected for their BM.Conclusions:Eccentric knee-flexor strength, as assessed with the Nordbord, is largely BM-dependent. To control for this effect, practitioners may compare actual test performances with the expected strength for a given BM, using the following predictive equation: Eccentric strength (N) = 4 × BM (kg) + 26.1. Professional soccer players with specific knee-flexor-training history and enhanced neuromuscular performance may show higher than expected values.


Author(s):  
Rhys Morris ◽  
Tony Myers ◽  
Stacey Emmonds ◽  
Dave Singleton ◽  
Kevin Till

Abstract Purpose Sled towing has been shown to be an effective method to enhance the physical qualities in youth athletes. The aim of this study was to evaluate the impact of a 6-week sled towing intervention on muscular strength, speed and power in elite youth soccer players of differing maturity status. Method Seventy-three male elite youth soccer players aged 12–18 years (Pre-Peak Height Velocity [PHV] n = 25; Circa-PHV n = 24; Post-PHV n = 24) from one professional soccer academy participated in this study. Sprint assessments (10 m and 30 m), countermovement jump and isometric mid-thigh pull were undertaken before (T1) and after (T2) a 6-week intervention. The training intervention consisted of 6 weeks (2 × per week, 10 sprints over 20 m distance) of resisted sled towing (linear progression 10%–30% of body mass) during the competitive season. Bayesian regression models analysed differences between T1 and T2 within each maturity group. Results There were minimal changes in strength, speed and power (P = 0.35–0.80) for each maturity group across the 6-week intervention. Where there were changes with greater certainty, they are unlikely to represent real effect due to higher regression to the mean (RTM). Conclusion It appears that a 6-week sled towing training programme with loadings of 10%–30% body mass only maintains physical qualities in elite youth soccer players pre-, circa-, and post-PHV. Further research is required to determine the effectiveness of this training method in long-term athletic development programmes.


Author(s):  
Hadi Nobari ◽  
Ana Ruivo Alves ◽  
Filipe Manuel Clemente ◽  
Jorge Pérez-Gómez

Abstract Background Digit ratio (2D:4D) characterized by the length of the second digit (2D) divided by the length of the fourth digit (4D), is a powerful marker of athletic performance. Some studies showed a negative correlation between 2D:4D ratio and sports performances. Objectives The purpose of the present study was three-fold: (1) to analyze the influence of anthropometric and 2D:4D ratio on variations of accumulated training load (ATL) and fitness parameters: maximal oxygen uptake (V̇O2max), countermovement jump (CMJ), isometric muscular strength of the knee extensor for hamstring (ISH) and flexor for quadriceps (ISQ) muscles; along three stages of evaluation of soccer players based on playing positions; (2) to analyze the correlations between 2D:4D ratio and aforementioned parameters; and (3) to investigate if variance in fitness levels and ATL can explain the 2D:4D ratio. Methods Twenty-four elite players under 17 years were daily monitored for their rating perceived exertion and ATL across 24 weeks over the season. Soccer players have also measured in three stages for anthropometric traits and fitness parameters. Results Significant differences were observed between playing positions for body mass, goalkeepers had higher body mass compared to centre-midfielder and winger players. Moreover, there were significant differences in ATL between early-season to mid-season in goalkeepers (P = 0.032). The 2D:4D ratio (left and right) shown largely and negatively association with muscular strength (ISQ: r =  − 0.80; r =  − 0.78, P ≤ 0.001, ISH: r =  − 0.63; r =  − 0.62, P = 0.001, respectively) and VO2max changes (r =  − 0.55, P = 0.005; r =  − 0.50, P = 0.013, respectively); lastly, both 2D:4D ratio significantly predicted changes in muscular strength and VO2max in young soccer players. Conclusions Goalkeepers tended to have higher body mass compared to centre-midfielder and winger players; and 2D:4D ratio revealed a mighty predictor of physical fitness changes in soccer players. Evidence should be helpful to professionals to highlight the usefulness of the 2D:4D into the identification of talent, but also to optimize young players' performance.


2017 ◽  
Vol 26 (5) ◽  
pp. 358-364 ◽  
Author(s):  
Anh-Dung Nguyen ◽  
Emma F. Zuk ◽  
Andrea L. Baellow ◽  
Kate R. Pfile ◽  
Lindsay J. DiStefano ◽  
...  

Context:Risk of anterior cruciate ligament (ACL) injuries in young female athletes increases with age, appearing to peak during maturation. Changes in hip muscle strength and range of motion (ROM) during this time may contribute to altered dynamic movement patterns that are known to increase risk of ACL injuries. Understanding the longitudinal changes in hip strength and ROM is needed to develop appropriate interventions to reduce the risk of ACL injuries.Objective:To examine the longitudinal changes in hip strength and ROM in female youth soccer players.Design:Longitudinal descriptive study.Setting:Field setting.Participants:14 female youth soccer athletes (14.1 ± 1.1 y, 165.8 ± 5.3 cm, 57.5 ± 9.9 kg) volunteered as part of a multiyear risk factor screening project.Main Outcome Measures:Clinical measures of hip strength and ROM were collected annually over 3 consecutive years. Passive hip internal rotation (IR), external rotation (ER), abduction (ABD), and adduction (ADD) ROM were measured with a digital inclinometer. Isometric hip ABD and extension (EXT) strength were evaluated using a hand-held dynamometer. Separate repeated-measures ANOVAs compared hip strength and ROM values across 3 consecutive years (P < .05).Results:As youth female soccer players increased in age, there were no changes in normalized hip ABD (P = .830) or EXT strength (P = .062) across 3 consecutive years. Longitudinal changes in hip ROM were observed with increases in hip IR (P = .001) and ABD (P < .001), while hip ADD (P = .009) and ER (P < .001) decreased.Conclusions:Anatomical changes at the hip occur as youth female soccer players increase in age. While there are no changes in hip strength, there is an increase in hip IR and ABD ROM with a concomitant decrease in hip ER and ADD ROM. The resulting asymmetries in hip ROM may decrease the activation and force producing capabilities of the hip muscles during dynamic activities, contributing to altered lower extremity mechanics known to increase the risk of ACL injuries.


2018 ◽  
Vol 13 (5) ◽  
pp. 674-678 ◽  
Author(s):  
Thomas E Brownlee ◽  
Andy O’Boyle ◽  
Ryland Morgans ◽  
James P Morton ◽  
Robert M Erskine ◽  
...  

Purpose To determine whether training duration is a predisposing factor in potential maladaptations in talent development programmes that promote early specialisation in elite youth soccer. Methods Training times and type of 184 elite soccer players, from the under-9 to under-21 age groups (age 9.4 to 18.4 yrs; stature 1.38 to 1.82 m; body mass 32.2 to 76.2 kg) were recorded. Results Total training time progressively increased between the under-9 (268 ± 25 min/week) and under-14 (477 ± 19 min/week) groups with the majority of training time (96.5 ± 3.9%) consisting of soccer training and matches. Total training time then subsequently reduced from under-14 to under-15 (266 ± 77 min/week) groups, with no differences in training time between under-15 and under-21. Only under-15 to under-21 players completed resistance training; this inclusion coincided with a reduction in soccer training and match play when compared to time spent in these activities for younger groups (73.8 ± 3.2% of total training). Conclusion Data suggest that although the majority of training is focused on technical development, the training duration as a whole is unlikely to contribute to potential maladaptations in talent development programmes in elite youth soccer.


2020 ◽  
Vol 15 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Mathieu Lacome ◽  
Simon Avrillon ◽  
Yannick Cholley ◽  
Ben M. Simpson ◽  
Gael Guilhem ◽  
...  

Aim: To compare the effect of low versus high volume of eccentric-biased hamstring training programs on knee-flexor strength and fascicle length changes in elite soccer players. Methods: A total of 19 elite youth soccer players took part in this study and were randomly assigned into 2 subgroups. For 6 weeks in-season, the groups performed either a low-volume (1 set per exercise; 10 repetitions in total) or a high-volume (4 sets; 40 repetitions) eccentric training of their knee flexors. After 6-weeks midtraining (MID), players performed the alternate training regimen. Each training set consisted of 4 repetitions of the Nordic hamstring exercise and 6 repetitions of the bilateral stiff-leg deadlift. Eccentric knee-flexor strength (NordBord) as well as biceps femoris long head and semimembranosus fascicle length (scanned with ultrasound scanner) were assessed during pretraining (PRE), MID, and posttraining (POST) tests. Results: Knee-flexor eccentric strength very likely increased from PRE to MID (low volume: +11.3% [7.8%] and high volume: 11.4% [5.3%]), with a possibly-to-likely increase in biceps femoris long head (+4.5% [5.0%] and 4.8% [2.5%]) and semimembranosus (+4.3% [4.7%] and 6.3% [6.3%]) fascicle length in both groups. There was no substantial changes between MID and POST. Overall, there was no clear between-group difference in the changes from PRE to MID and MID to POST for neither knee-flexor eccentric strength, biceps femoris long head, nor semimembranosus fascicle length. Conclusions: Low-volume knee-flexor eccentric training is as effective as a greater training dose to substantially improve knee-flexor strength and fascicle length in-season in young elite soccer players. Low volume is, however, likely more appropriate to be used in an elite team facing congested schedules.


2013 ◽  
Vol 22 (2) ◽  
pp. 100-107 ◽  
Author(s):  
Jacqueline Vieira de Castro ◽  
Karina Costa Machado ◽  
Kelly Scaramussa ◽  
João Luiz Ellera Gomes

Context:After years of focusing on the management of anterior cruciate ligament (ACL) injuries, the most common soccer-related injuries, the orthopedic community has concluded that soccer players have a wide range of variation in joint biomechanics and has thus started to focus research efforts on the morphological factors that might contribute to ACL trauma. One such factor is decreased hip-rotation range of motion (ROM), which may be due to compensatory musculoskeletal changes occurring in response to longstanding soccer practice since childhood.Objective:This study sought to assess decreased hip rotation and the influence of stretching exercises on the behavior of the hip joint in players of the youth soccer categories of a Brazilian soccer team.Design:Randomized clinical trial.Setting:University hospital.Patients:262 male soccer players.Interventions:Subjects were randomly allocated into 2 groups—control or a stretching program.Main Outcome Measures:Subjects were reassessed after 12 wk.Results:The findings suggest that hip-rotation ROM decreases over the years in soccer players. In the study sample, adherence to a stretching program improved only external hip-rotation ROM in the nondominant limb.Conclusion:Playing soccer can restrict rotation ROM of the hip, and adherence to stretching exercises may decrease the harmful effects on the hip joints.


2014 ◽  
Vol 42 (1) ◽  
pp. 259-266 ◽  
Author(s):  
Yara Lucy Fidelix ◽  
Juliane Berria ◽  
Elisa Pinheiro Ferrari ◽  
Jaelson Gonçalves Ortiz ◽  
Tiago Cetolin ◽  
...  

Abstract The aim of this study was to identify the morphological configuration of youth athletes from professional soccer clubs and to verify their differences according to the tactical position on the field. Overall, 67 male players aged 15 to 17 years were evaluated. The examined anthropometric measurements included body mass, body height, skinfolds (triceps, subscapular, supraspinal and medial calf), girths (flexed and tensed arm and calf) and breadths (humerus and femur). For statistical purposes, analysis of variance and post hoc Bonferroni and Kruskal-Wallis tests were used. We concluded that goalkeepers were heavier and taller than center backs (p = 0.015 and p = 0.001), midfielders (p = 0.005 and p <0.001) and center forward players (p = 0.024 and p <0.001). The average somatotype for defense, forward and goalkeeper positions was a balanced mesomorph. Midfield players showed ectomorphic-mesomorph characteristics. It was concluded that goalkeepers were characterized as being taller and heavier and that somatotype features of athletes were similar between positions, except for midfield players


2013 ◽  
Vol 22 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Moisés de Hoyo ◽  
Alejandro Álvarez-Mesa ◽  
Borja Sañudo ◽  
Luis Carrasco ◽  
Sergio Domínguez

Context:Kinesio taping (KT) is a new taping technique increasingly used in sports medicine to improve muscle performance; however, its real effect is not entirely known.Objective:To assess the immediate effects of KT on muscle performance in young healthy elite soccer players.Design:Crossover study.Setting:University laboratory.Participants:Eighteen young elite soccer players voluntarily participated in the study (mean ± SEM: age 18.20 ± 2.45 y, height 1.76 ± 3.56 m, body mass 65.25 ± 3.76 kg, body-mass index 20.12 ± 1.25 kg/m2).Interventions:Each subject completed 2 different protocols, with and without KT. Interventions were performed in a random order, with a washout period between conditions of 1 wk.Main Outcome Measures:Outcome measures included tensiomyographic response in the vastus lateralis and vastus medialis, power output with 30 and 50 kg, countermovement jump, and 10-m sprint.Results:Data showed no significant differences for any of the outcomes analyzed between interventions.Conclusions:KT does not produce a short-term improvement in muscle performance in young elite soccer players.


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