Hamstring muscle architecture and myotonometer measurements in elite professional football players with a prior strained hamstring

The COVID-19 pandemic has produced a major disruption for professional football leagues that has affected the physical preparation of both football players and referees. In Spain, health authorities decreed home confinement for eight weeks, supressing the normal training routines of professional referees. After home confinement, referees had four weeks to retrain as the national football league was set to resume matches to complete the 11 games remaining. The aim of the present investigation was to assess changes in eccentric hamstring muscle strength during football competition suspension/resumption due to the COVID-19 pandemic in 21 professional football referees (mean ± SD, age: 33.4 ± 5.1 years; height: 182.4 ± 5.0 cm; body mass: 75.1 ± 4.4 kg). Eccentric hamstring muscle strength was measured with the Nordic hamstring exercise at four time points. During home confinement, referees presented the lowest value of bilateral eccentric muscle strength (300 ± 14 N). Eccentric muscle strength increased by 13.2 ± 3.7% one week after the end of home confinement (339 ± 16 N; p = 0.001, effect size (ES) = 2.8) and remained stable before the first match (343 ± 17 N; p = 0.001, ES = 3.1) and after the end of the national league (328 ± 13 N; p = 0.001, ES = 2.0). In summary, home confinement produced detraining effects in professional football referees associated with hamstring muscle weakness. In this regard, strength-based activities with body loads may be insufficient to avoid muscle weakness and other means (e.g., weights) may be necessary to maintain muscle strength. However, the 4-weeks retraining period was sufficient to resolve hamstring muscle weakness induced by the restrictions of home confinement. This information may be helpful in the case of future sport competition suspension or home quarantine due to new waves of COVID-19 pandemic.

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Post-match recovery of eccentric knee flexor strength in male professional football players

Physical Therapy in Sport ◽

10.1016/j.ptsp.2020.11.032 ◽

2021 ◽

Vol 47 ◽

pp. 140-146

Author(s):

César Augusto Bueno ◽

João Breno de Araujo Ribeiro-Alvares ◽

Gabriel dos Santos Oliveira ◽

Rafael Grazioli ◽

Filipe Veeck ◽

...

Keyword(s):

Football Players ◽

Professional Football ◽

Knee Flexor ◽

Flexor Strength

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Lunate and Perilunate Dislocations in Professional Football Players

The American Journal of Sports Medicine ◽

10.1177/036354659402200617 ◽

1994 ◽

Vol 22 (6) ◽

pp. 841-845 ◽

Cited By ~ 17

Author(s):

David J. Raab ◽

David A. Fischer ◽

Donald C. Quick

Keyword(s):

Football Players ◽

Professional Football

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Anterior Cruciate Ligament Injury Prevention Exercises: Could a Neuromuscular Warm-Up Improve Muscle Pre-Activation before a Soccer Game? A Proof-of-Principle Study on Professional Football Players

Applied Sciences ◽

10.3390/app11114958 ◽

2021 ◽

Vol 11 (11) ◽

pp. 4958

Author(s):

Alessandro de Sire ◽

Andrea Demeco ◽

Nicola Marotta ◽

Lucrezia Moggio ◽

Arrigo Palumbo ◽

...

Keyword(s):

Anterior Cruciate Ligament ◽

Cruciate Ligament ◽

Acl Injury ◽

Football Players ◽

Professional Football ◽

Activation Time ◽

Exercise Protocol ◽

Warm Up ◽

Anterior Cruciate ◽

Proof Of Principle

Neuromuscular warm-up has been shown to decrease the risk of anterior cruciate ligament (ACL) injury improving muscular firing patterns. All preventive training programs described in the literature have a duration of several weeks. To date, no studies have explored the immediate effect of a neuromuscular warm-up exercise on pre-activation time of the knee stabilizer muscles. Thus, this proof-of-principle study aimed at evaluating the acute effects of a neuromuscular warm-up exercises on the electromyographic activation of knee stabilizer muscles’ activation pattern. We included 11 professional football players, mean aged 23.2 ± 4.5 years, from a Southern Italy football team. All of them underwent a standard warm-up exercise protocol at the first day of the evaluation. At 1 week, they underwent a structured neuromuscular warm-up exercise protocol. We assessed as outcome measure the pre-activation time (ms) of rectus femoris (RF), vastus medialis (VM), biceps femoris (BF), and medial hamstrings (MH) upon landing. Outcomes were assessed before and after the standard warm-up and neuromuscular warm-up. Pre-activation time of RF, VM, BF and MH significantly improved only after neuromuscular warm-up (p < 0.05); moreover, there was a significant (p < 0.05) between-group difference in pre-activation time of all muscles after the neuromuscular warm-up compared with the standard warm-up. These findings suggested that physical exercise consisting of a structured injury prevention neuromuscular warm-up might have an immediate effect in improving the activation time of the knee stabilizer muscles, thus potentially reducing the risk of ACL injury.

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Resuming professional football (soccer) during the COVID-19 pandemic in a country with high infection rates: a prospective cohort study

British Journal of Sports Medicine ◽

10.1136/bjsports-2020-103724 ◽

2021 ◽

pp. bjsports-2020-103724

Author(s):

Yorck Olaf Schumacher ◽

Montassar Tabben ◽

Khalid Hassoun ◽

Asmaa Al Marwani ◽

Ibrahim Al Hussein ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Preventive Measures ◽

Clinical Symptoms ◽

Severe Illness ◽

Football Players ◽

Professional Football ◽

Infection Rates ◽

High Infection

ObjectivesThe risk of viral transmission associated with contact sports such as football (soccer) during the COVID-19 pandemic is unknown. The aim of this study was to describe the infective and immune status of professional football players, team staff and league officials over a truncated football season resumed at the height of the COVID-19 pandemic in a country with high infection rates and to investigate the clinical symptoms related to COVID-19 infection in professional football players.MethodsProspective cohort study of 1337 football players, staff and officials during a truncated football season (9 weeks) with a tailored infection control programme based on preventive measures and regular SARS-CoV-2 PCR swab testing (every 3–5 days) combined with serology testing for immunity (every 4 weeks). Clinical symptoms in positive participants were recorded using a 26-item, Likert-Scale-based scoring system.ResultsDuring the study period, 85 subjects returned positive (cycle threshold (cT) ≤30) or reactive (30<cT<40) PCR tests, of which 36 were players. The infection rate was consistent with that of the general population during the same time period. More than half of infected subjects were asymptomatic, and the remaining had only mild symptoms with no one requiring hospitalisation. Symptom severity was associated with lower cT values. Social contacts and family were the most common sources of infection, and no infection could be traced to training or matches. Of the 36 infected players, 15 presented positive serology during the study period.ConclusionFootball played outdoors involving close contact between athletes represents a limited risk for SARS-CoV-2 infection and severe illness when preventive measures are in place.

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Injury rates decreased in men’s professional football: an 18-year prospective cohort study of almost 12 000 injuries sustained during 1.8 million hours of play

British Journal of Sports Medicine ◽

10.1136/bjsports-2020-103159 ◽

2021 ◽

pp. bjsports-2020-103159

Author(s):

Jan Ekstrand ◽

Armin Spreco ◽

Håkan Bengtsson ◽

Roald Bahr

Keyword(s):

Ligament Injury ◽

Football Players ◽

Injury Incidence ◽

Professional Football ◽

Muscle Injuries ◽

Time Loss ◽

Match Play ◽

Injury Rates ◽

Surveillance Programme ◽

Individual Player

BackgroundThe UEFA Elite Club Injury Study is the largest and longest running injury surveillance programme in football.ObjectiveTo analyse the 18-season time trends in injury rates among male professional football players.Methods3302 players comprising 49 teams (19 countries) were followed from 2000–2001 through 2018–2019. Team medical staff recorded individual player exposure and time-loss injuries.ResultsA total of 11 820 time-loss injuries were recorded during 1 784 281 hours of exposure. Injury incidence fell gradually during the 18-year study period, 3% per season for both training injuries (95% CI 1% to 4% decrease, p=0.002) and match injuries (95% CI 2% to 3% decrease, p<0.001). Ligament injury incidence decreased 5% per season during training (95% CI 3% to 7% decrease, p<0.001) and 4% per season during match play (95% CI 3% to 6% decrease, p<0.001), while the rate of muscle injuries remained constant. The incidence of reinjuries decreased by 5% per season during both training (95% CI 2% to 8% decrease, p=0.001) and matches (95% CI 3% to 7% decrease, p<0.001). Squad availability increased by 0.7% per season for training sessions (95% CI 0.5% to 0.8% increase, p<0.001) and 0.2% per season for matches (95% CI 0.1% to 0.3% increase, p=0.001).ConclusionsOver 18 years: (1) injury incidence decreased in training and matches, (2) reinjury rates decreased, and (3) player availability for training and match play increased.

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High rate of second ACL injury following ACL reconstruction in male professional footballers: an updated longitudinal analysis from 118 players in the UEFA Elite Club Injury Study

British Journal of Sports Medicine ◽

10.1136/bjsports-2020-103555 ◽

2021 ◽

pp. bjsports-2020-103555

Author(s):

Francesco Della Villa ◽

Martin Hägglund ◽

Stefano Della Villa ◽

Jan Ekstrand ◽

Markus Waldén

Keyword(s):

Acl Reconstruction ◽

Cox Regression ◽

Injury Rate ◽

Acl Injury ◽

High Rate ◽

Football Players ◽

Professional Football ◽

Cox Regression Analysis ◽

Career Length ◽

Increased Risk

BackgroundStudies on subsequent anterior cruciate ligament (ACL) ruptures and career length in male professional football players after ACL reconstruction (ACLR) are scarce.AimTo investigate the second ACL injury rate, potential predictors of second ACL injury and the career length after ACLR.Study designProspective cohort study.SettingMen’s professional football.Methods118 players with index ACL injury were tracked longitudinally for subsequent ACL injury and career length over 16.9 years. Multivariable Cox regression analysis with HR was carried out to study potential predictors for subsequent ACL injury.ResultsMedian follow-up was 4.3 (IQR 4.6) years after ACLR. The second ACL injury rate after return to training (RTT) was 17.8% (n=21), with 9.3% (n=11) to the ipsilateral and 8.5% (n=10) to the contralateral knee. Significant predictors for second ACL injury were a non-contact index ACL injury (HR 7.16, 95% CI 1.63 to 31.22) and an isolated index ACL injury (HR 2.73, 95% CI 1.06 to 7.07). In total, 11 of 26 players (42%) with a non-contact isolated index ACL injury suffered a second ACL injury. RTT time was not an independent predictor of second ACL injury, even though there was a tendency for a risk reduction with longer time to RTT. Median career length after ACLR was 4.1 (IQR 4.0) years and 60% of players were still playing at preinjury level 5 years after ACLR.ConclusionsAlmost one out of five top-level professional male football players sustained a second ACL injury following ACLR and return to football, with a considerably increased risk for players with a non-contact or isolated index injury.

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