The acute:chonic workload ratio in relation to injury risk in professional soccer

Context: Injuries are a major adverse event in a soccer player's career. Reducing injury incidence requires a thorough knowledge of the epidemiology of soccer injuries. Objective: To investigate the incidence and characteristics of injuries in the Dutch premier soccer league. Design: Cohort study. Setting: The Dutch premier soccer league. Patients or Other Participants: During the 2009–2010 soccer season, a total of 217 professional soccer players from 8 teams were prospectively followed. Main Outcome Measure(s): The medical staff recorded time-loss injuries, including information on injuries (ie, type, body part, duration) and exposure data for training sessions and matches. Results: A total of 286 injuries were recorded, affecting 62.7% of the players. The overall injury incidence was 6.2 injuries per 1000 player-hours, 2.8 in training sessions and 32.8 in matches. Most of the recorded injuries were acute (68.5%). Eight percent of the injuries were classified as recurrent. Injuries were most likely to be located in the lower extremities (82.9%). Injury time loss ranged from 1 to 752 days, with a median of 8 days. Knee injuries had the greatest consequences in terms of days of absence from soccer play (on average, 45 days). The most common diagnosis was muscle/tendon injury of the lower extremities (32.9%). Conclusions: Injury risk in the Dutch premier soccer league is high, especially during matches. Preventive measures should focus on the most common diagnoses, namely, muscle/tendon injuries of the lower extremities.

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Differences in injury risk and characteristics between Dutch amateur and professional soccer players

Journal of Science and Medicine in Sport ◽

10.1016/j.jsams.2014.02.004 ◽

2015 ◽

Vol 18 (2) ◽

pp. 145-149 ◽

Cited By ~ 41

Author(s):

A.M.C. (Anne-Marie) van Beijsterveldt ◽

J.H. Stubbe ◽

S.L. Schmikli ◽

I.G.L. van de Port ◽

F.J.G. Backx

Keyword(s):

Injury Risk ◽

Soccer Players ◽

Professional Soccer

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Evaluating injury risk in first and second league professional Portuguese soccer: muscular strength and asymmetry

Journal of Human Kinetics ◽

10.1515/hukin-2015-0166 ◽

2016 ◽

Vol 51 (1) ◽

pp. 19-26 ◽

Cited By ~ 9

Author(s):

Alberto Carvalho ◽

Scott Brown ◽

Eduardo Abade

Keyword(s):

Muscle Strength ◽

Injury Risk ◽

Dynamic Control ◽

Peak Torque ◽

Soccer Players ◽

Bilateral Asymmetry ◽

Hamstring Strain ◽

Professional Soccer ◽

Maximal Peak ◽

The Right

AbstractStrength imbalances between the hamstrings and quadriceps are an essential predictor for hamstring strain in soccer. The study aimed to investigate and compare the muscle strength imbalances of professional soccer players of different performance levels. One hundred and fifty nine senior male professional soccer players from first (n = 75) and second league (n = 84) Portuguese clubs participated in this study. Muscle strength was evaluated with a REV9000 isokinetic dynamometer. Maximal peak torque data were used to calculate quadriceps and hamstrings strength during concentric and eccentric actions, bilateral asymmetry, conventional strength ratios and dynamic control ratios. Second league athletes produced slightly lower conventional strength ratios in the right and left legs (ES = 0.22, p = 0.17 and ES = 0.36, p = 0.023, respectively) compared to the first league athletes. No significant differences were found in dynamic control ratios or in bilateral asymmetry among first and second league athletes. These findings do not show a clear link between the competitive level and injury risk in soccer players. However, some of the differences found, particularly in conventional strength ratios, highlight the importance of performing off-season and pre-season strength assessments to prescribe and adjust individual strength training programs among professional soccer players.

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Blood Biomarkers Variations across the Pre-Season and Interactions with Training Load: A Study in Professional Soccer Players

Journal of Clinical Medicine ◽

10.3390/jcm10235576 ◽

2021 ◽

Vol 10 (23) ◽

pp. 5576

Author(s):

Filipe Manuel Clemente ◽

Francisco Tomás González-Fernández ◽

Halil Ibrahim Ceylan ◽

Rui Silva ◽

Saeid Younesi ◽

...

Keyword(s):

Injury Risk ◽

Perceived Exertion ◽

Hematological Parameters ◽

Blood Parameters ◽

Training Load ◽

Soccer Players ◽

Immune Functions ◽

Professional Soccer ◽

Biochemical Analyses ◽

And Training

Background: Pre-season training in soccer can induce changes in biological markers in the circulation. However, relationships between chosen hematological and biochemical blood parameters and training load have not been measured. Objective: Analyze the blood measures changes and their relationships with training loads changes after pre-season training. Methodology: Twenty-five professional soccer players were assessed by training load measures (derived from rate of perceived exertion- known as RPE) during the pre-season period. Additionally, blood samples were collected for hematological and biochemical analyses. Results: For hematological parameters, significant increases were found for platelets (PLT) (dif: 6.42; p = 0.006; d = −0.36), while significant decreases were found for absolute neutrophils count (ANC) (dif: −3.98; p = 0.006; d = 0.11), and absolute monocytes count (AMC) (dif: −16.98; p = 0.001; d = 0.78) after the pre-season period. For biochemical parameters, there were significant increases in creatinine (dif: 5.15; p = 0.001; d = −0.46), alkaline phosphatase (ALP) (dif: 12.55; p = 0.001; d = −0.84), C-reactive protein (CRP) (dif: 15.15; p = 0.001; d = −0.67), cortisol (dif: 2.85; p = 0.001; d = −0.28), and testosterone (dif: 5.38; p = 0.001; d = −0.52), whereas there were significant decreases in calcium (dif: −1.31; p = 0.007; d =0.49) and calcium corrected (dif: −2.18; p = 0.015; d = 0.82) after the pre-season period. Moreover, the Hooper Index (dif: 13.22; p = 0.01; d = 0.78), and all derived RPE measures increased after pre-season period. Moderate-to-very large positive and negative correlations (r range: 0.50–0.73) were found between the training load and hematological measures percentage of changes. Moderate-to-large positive and negative correlations (r range: 0.50–0.60) were found between training load and biochemical measures percentage of changes. Conclusions: The results indicated heavy physical loads during the pre-season, leading to a decrease in immune functions. Given the significant relationships between blood and training load measures, monitoring hematological and biochemical measures allow coaches to minimize injury risk, overreaching, and overtraining.

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A Preventive Model for Hamstring Injuries in Professional Soccer: Learning Algorithms

International Journal of Sports Medicine ◽

10.1055/a-0826-1955 ◽

2019 ◽

Vol 40 (05) ◽

pp. 344-353 ◽

Cited By ~ 6

Author(s):

Francisco Ayala ◽

Alejandro López-Valenciano ◽

Jose Antonio Gámez Martín ◽

Mark De Ste Croix ◽

Francisco Vera-Garcia ◽

...

Keyword(s):

Injury Risk ◽

Factor Model ◽

Characteristic Curve ◽

Predictive Ability ◽

True Positive Rate ◽

Machine Learning Techniques ◽

Soccer Players ◽

True Negative ◽

Professional Soccer ◽

Hamstring Injuries

AbstractHamstring strain injury (HSI) is one of the most prevalent and severe injury in professional soccer. The purpose was to analyze and compare the predictive ability of a range of machine learning techniques to select the best performing injury risk factor model to identify professional soccer players at high risk of HSIs. A total of 96 male professional soccer players underwent a pre-season screening evaluation that included a large number of individual, psychological and neuromuscular measurements. Injury surveillance was prospectively employed to capture all the HSI occurring in the 2013/2014 season. There were 18 HSIs. Injury distribution was 55.6% dominant leg and 44.4% non-dominant leg. The model generated by the SmooteBoostM1 technique with a cost-sensitive ADTree as the base classifier reported the best evaluation criteria (area under the receiver operating characteristic curve score=0.837, true positive rate=77.8%, true negative rate=83.8%) and hence was considered the best for predicting HSI. The prediction model showed moderate to high accuracy for identifying professional soccer players at risk of HSI during pre-season screenings. Therefore, the model developed might help coaches, physical trainers and medical practitioners in the decision-making process for injury prevention.

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Comparisons of new body load and metabolic power average workload indices between starters and non-starters: A full-season study in professional soccer players

Proceedings of the Institution of Mechanical Engineers Part P Journal of Sports Engineering and Technology ◽

10.1177/1754337120974873 ◽

2020 ◽

pp. 175433712097487

Author(s):

Hadi Nobari ◽

Gibson Moreira Praça ◽

Filipe Manuel Clemente ◽

Jorge Pérez-Gómez ◽

Jorge Carlos Vivas ◽

...

Keyword(s):

Injury Risk ◽

Soccer Players ◽

Metabolic Power ◽

Early Season ◽

Professional Soccer ◽

Weekly Training ◽

Significant Difference ◽

Body Load ◽

Gps Devices ◽

And Training

The aim of this study was to compare the weekly average training monotony new body load (wTMNBL) and strain (wTSNBL), as well as the weekly average training monotony metabolic power average (wTMMPA) and strain (wTSMPA) between four periods of a season (preseason, early-season, mid-season, and end-season), considering starters and non-starters. Twenty-one professional soccer players (age: 28.27 ± 3.78 years) were monitored throughout a season in the highest level of professional football Premier League in Iran. Data were captured by Global Positioning System (GPS) devices. Independent samples T-tests were applied to analyze the between-group differences for all dependent derived-GPS variables for the full season and its different periods (preseason, early-season, mid-season, and end-season). Based on the amount of time attending in match and training, players were divided into two groups (starters and non-starters) each week. The magnitude of the between-group difference revealed a very large significant greater weekly average TMNBL ( p<0.001, d = −2.42), TSNBL ( p<0.001; d = −2.74), TMMPA ( p<0.001; d =–2.79) and TSMPA ( p<0.001; d = −3.27) for starters when compared to non-starters during the early-season. The findings also revealed a very large significant difference when starters were compared to non-starters during the mid-season (TMNBL: p<0.001, d = −2.89; TSNBL: p<0.001, d = −2.99; TMMPA: p<0.001, d = −3.28; and TSMPA: p<0.001, d = −3.25) and end-season (TMNBL: p<0.001, d = −2.89; TSNBL: p<0.001, d = −3.07; TMMPA: p<0.001, d = −3.16; and TSMPA: p<0.001, d = −3.58). In summary, the results of this study revealed that starters present regularly higher values of NBL, MPA-based weekly training monotony, and training strain than non-starters. This result must be taken into account when planning weekly workloads for these groups. Specifically, starters might experience high values of external workloads because of match-related demands. Therefore, weekly adjustments in their training workload are required to reduce injury risk.

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The within-match patterns of locomotor efficiency during professional soccer match play: Implications for injury risk?

Journal of Science and Medicine in Sport ◽

10.1016/j.jsams.2015.12.514 ◽

2016 ◽

Vol 19 (10) ◽

pp. 810-815 ◽

Cited By ~ 21

Author(s):

Steve Barrett ◽

Adrian Midgley ◽

Matt Reeves ◽

Tom Joel ◽

Ed Franklin ◽

...

Keyword(s):

Injury Risk ◽

Match Play ◽

Soccer Match ◽

Professional Soccer

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Workload is Associated with the Occurrence of Non-Contact Injuries in Professional Male Soccer Players: A Pilot Study

10.21203/rs.3.rs-390515/v1 ◽

2021 ◽

Author(s):

Hadi Nobari ◽

Sara Mahmoudzadeh Khalili ◽

Angel Denche Zamorano ◽

Thomas G. Bowman ◽

Jose Carmelo Adsuar ◽

...

Keyword(s):

Injury Risk ◽

High Load ◽

Soccer Players ◽

Time Interval ◽

Expected Time ◽

Professional Soccer ◽

Increased Risk ◽

Low Load ◽

High Workload ◽

Type Of Injury

Abstract Background: Injuries in professional soccer are a significant concern for teams, and they are, mostly, caused by high training load. This cohort study described the relationship between workload parameters with the occurrence of non-contact injuries, during weeks with high and low workload in professional soccer players throughout the season.Methods: Twenty-one professional soccer players aged 28.3±3.9 yrs. who competed in the Iranian Persian Gulf Pro League participated in this 48-week study. The external load was monitored using global positioning system (GPS, GPSPORTS Systems Pty Ltd) and the type of injury was documented by the team's medical staff daily. Odds ratio (OR) and relative risk (RR) were calculated for non-contact injuries for high- and low-load weeks according to acute (AW), chronic (CW), acute to chronic workload ratio (ACWR), and AW variation (Δ-Acute) values. By using Poisson distribution, the interval between previous and new injuries were estimated.Results: Overall, 12 non-contact injuries occurred during high load and 9 during low load weeks. Based on the variables ACWR and Δ-AW, there was a significantly increased risk of sustaining non-contact injuries (p < 0.05) during high-load weeks for ACWR (OR: 4.67), and Δ-AW (OR: 4.07). Finally, the expected time between injuries was significantly shorter in high load weeks for ACWR [1.25 vs 3.33, rate ratio time (RRT)] and Δ-AW [1.33 vs 3.45, RRT] respectively, compared to low load weeks.Conclusion: The risk of sustaining injuries was significantly larger during high workload weeks for ACWR, and Δ-AW compared with low workload weeks. The high numbers for OR in high load weeks indicate that there is a significant relationship between workload and occurrence of non-contact injuries. The predicted time to new injuries is shorter in high load weeks compared to low load weeks. Therefore, the frequency of injuries is higher during high load weeks for ACWR and Δ-AW. ACWR and Δ-AW appear to be good indicators for estimating the injury risk, and the time interval between injuries.

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The Use of Recovery Strategies in Professional Soccer: A Worldwide Survey

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2020-0799 ◽

2021 ◽

pp. 1-12

Author(s):

Adam Field ◽

Liam D. Harper ◽

Bryna C.R. Chrismas ◽

Peter M. Fowler ◽

Alan McCall ◽

...

Keyword(s):

Performance Optimization ◽

Injury Risk ◽

Cold Water ◽

Strategy Use ◽

Perceived Effectiveness ◽

Active Recovery ◽

Cross Sectional ◽

Convenience Sample ◽

Professional Soccer ◽

Recovery Strategies

Purpose: To survey soccer practitioners’ recovery strategy: (1) use, (2) perceived effectiveness, and (3) factors influencing their implementation in professional soccer. Methods: A cross-sectional convenience sample of professional soccer club/confederation practitioners completed a web-based survey (April to July 2020). Pearson chi-square and Fisher exact tests with Cramer V (φ − c) assessed relationships and their strength, respectively, between the perceived effectiveness and frequency of strategy use. Results: A total of 80 soccer practitioners (13 countries) completed the survey. The 3 most important recovery objectives were “alleviating muscle damage/fatigue,” “minimizing injury risk,” and “performance optimization.” The most frequently used strategies were active recovery, structured recovery day, extra rest day, massage, cold-water therapy, and carbohydrate provision (predominantly on match day and match day + 1). Relationships were identified between perceived effectiveness and frequency of strategy use for sleep medication (P < .001, φ − c = 0.48), carbohydrate provision (P = .007, φ − c = 0.60), protein provision (P = .007, φ − c = 0.63), an extra rest day (P < .001, φ − c = 0.56), and a structured recovery day (P = .049, φ − c = 0.50). Conclusions: The study demonstrates that professional soccer practitioners have a range of objectives geared toward enhancing player recovery. A disconnect is apparent between the perceived effectiveness of many recovery strategies and their frequency of use in an applied setting. Novel data indicate that strategies are most frequently employed around match day. Challenges to strategy adoption are mainly competing disciplinary interests and resource limitations. Researchers and practitioners should liaise to ensure that the complexities involved with operating in an applied environment are elucidated and apposite study designs are adopted, in turn, facilitating the use of practically effective and compatible recovery modalities.

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Training Management of the Elite Adolescent Soccer Player throughout Maturation

Sports ◽

10.3390/sports9120170 ◽

2021 ◽

Vol 9 (12) ◽

pp. 170

Author(s):

Alistair J. McBurnie ◽

Thomas Dos’Santos ◽

David Johnson ◽

Edward Leng

Keyword(s):

Athletic Performance ◽

Injury Risk ◽

Performance Monitoring ◽

Soccer Player ◽

Training Programme ◽

Soccer Players ◽

Youth Soccer ◽

Professional Soccer ◽

Data Informed ◽

Multi Disciplinary Team

Professional soccer clubs invest significantly into the development of their academy prospects with the hopes of producing elite players. Talented youngsters in elite development systems are exposed to high amounts of sports-specific practise with the aims of developing the foundational skills underpinning the capabilities needed to excel in the game. Yet large disparities in maturation status, growth-related issues, and highly-specialised sport practise predisposes these elite youth soccer players to an increased injury risk. However, practitioners may scaffold a performance monitoring and injury surveillance framework over an academy to facilitate data-informed training decisions that may not only mitigate this inherent injury risk, but also enhance athletic performance. Constant communication between members of the multi-disciplinary team enables context to build around an individual’s training status and risk profile, and ensures that a progressive, varied, and bespoke training programme is provided at all stages of development to maximise athletic potential.

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