Latest research in football - week 20 -2020

As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases.

Following studies were retrieved for this week:

#1 How does mental fatigue affect soccer performance during small-sided games? A cognitive, tactical and physical approach
Reference: J Sports Sci. 2020 May 2:1-11. doi: 10.1080/02640414.2020.1756681. [Epub ahead of print]
Authors: Kunrath CA, Nakamura FY, Roca A, Tessitore A, Teoldo Da Costa I
Summary: We examine how mental fatigue (MF) influences peripheral perception, tactical behaviour, and physical performance of soccer players during a standardized small-sided game. Eighteen male university first-team soccer players participated. A modified Stroop task and the Vienna Test System were employed to induce MF and to evaluate players' peripheral perception, respectively. The FUT-SAT test was used to assess participants' tactical behaviour and physical performance was quantified using GPS technology. MF decreased players' visual field (pre-test = 189.9° and post-test = 181.6°). Additionally, MF constrained players to more frequently perform actions related to the tactical principles of penetration, depth mobility, and defensive unity, and less frequently perform actions of defensive coverage and balance. During MF, players showed decreased accuracy in actions related to the principles of offensive coverage, width and length, offensive unity, delay, balance, concentration, and defensive unity. Finally, under MF players covered higher total distance and at more moderate speed. MF decreased players' peripheral perception, making them prioritize actions towards the opposing goal and protecting their own goal, while displaying more errors for most tactical actions. In summary, MF impaired several aspects of players' cognitive and tactical behaviours, causing a compensatory increase in physical performance.

#2 Return to Play and Career Length After Anterior Cruciate Ligament Reconstruction Among Canadian Professional Football Players
Reference: Am J Sports Med. 2020 May 7:363546520918224. doi: 10.1177/0363546520918224. [Epub ahead of print]
Authors: Longstaffe R, Leiter J, Gurney-Dunlop T, McCormack R, MacDonald P
Summary: For many athletes, a tear of the anterior cruciate ligament (ACL) represents a significant injury that requires a prolonged period away from the sport with substantial rehabilitation. There will be no difference in return to play (RTP) and career length after hamstring tendon (HT) ACL reconstruction in a group of Canadian Football League professional players as compared with what has been already been reported in the literature among professional football players. Data on athletes who sustained an ACL injury were collected by team physicians and head athletic trainers from 2002 to 2017 from 2 Canadian Football League teams. Patient details included age at the time of injury, initial injury date, position, practice versus game injury, and primary versus rerupture with injury-specific data, such as affected limb, concomitant injuries, graft choice, and procedure performed. RTP rates and career length data were collected through publically available internet sources. Comparisons between the non-RTP and RTP groups were made with independent-sample t tests. Binomial logistic regression was performed to determine variables (ie, games preinjury, graft type, meniscal injury, collateral ligament injury) that contributed to players not being able to RTP. A total of 44 ACL reconstructions were performed over the study period (HT, n = 32 [72.7%]; bone-patellar tendon-bone [BPTB], n = 8 [18.2%]; allograft, n = 4 [9.1%]). Overall, 69.8% (n = 30) were able to RTP in at least 1 game, while 30.2% (n = 13) did not return. Mean time to return was 316.1 days (range, 220-427 days), or 10.4 months. For those players who did RTP, mean career length after ACL reconstruction was 2.8 seasons, or 34.4 games. The majority (56.8%) of injuries occurred early in the season. Breakdown by graft type demonstrated RTP rates among HT, BPTB, and allograft of 64.5% (n = 20), 87.5% (n = 7), and 75% (n = 3), respectively. Career length among HT, BPTB, and allograft was 2.9, 2.4, and 3 seasons. Logistic regression analysis found only concomitant medial collateral ligament (MCL) injuries to be a negative predictor for RTP. Meniscal injuries were associated with a decreased RTP rate and career length, but this was not statistically significant. The RTP rates after ACL reconstruction in this study are similar to those reported in National Football League players. A concomitant injury to the MCL injury was a negative predictor of RTP. Meniscal injuries demonstrated a trend for decreased RTP rate and career length, but this was not a significant predictor. A large portion of injuries occur early in the season, and further study should be done to examine potential preventative strategies to reduce ACL injuries.

#3 Comparing Psychopathological Symptoms in Portuguese Football Fans and Non-Fans
Reference: Behav Sci (Basel). 2020 May 1;10(5). pii: E85. doi: 10.3390/bs10050085.
Authors: Leite Â, Ramires A, Costa R, Castro F, Sousa HFPE, Vidal DG, Dinis MAP
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Summary: The present study aims to characterize football fans and non-fans and to compare their psychopathological symptoms with the latest normative values for the Portuguese population from Canavarro in 2007. Results showed that football fans and non-fans are mostly male, have an affective relationship, are childless, have secondary education or a high degree, and are employed or students; fans are more likely to be male, dating, unemployed, to have elementary education and be younger than non-fans. Football fans present significantly higher psychopathological symptoms than non-fans in somatization, interpersonal sensitivity, anxiety, hostility, paranoid ideation and psychoticism and all psychopathological indexes. Football fans present values very close to those of populations with emotional distress in hostility and are above the mean of the general population in obsession-compulsion, hostility, paranoid ideation and psychoticism.

#4 Barriers and Enablers to Implementing Mental Well-being Programs Through Australian Rural Football Clubs - A Qualitative Descriptive Study
Reference: Health Promot J Austr. 2020 May 3. doi: 10.1002/hpja.358. [Epub ahead of print]
Authors: Hutchesson H, Dollman J, Baker A, Kernot J
Summary: Suicide rates in rural Australia are almost twice as high as those in urban areas. In rural communities, football clubs are often the 'hub' of the community and are being explored as an avenue to deliver mental health and wellbeing promotion. The aim of this study was to explore barriers and enablers for programs promoting mental health and wellbeing through rural Australian football clubs. This qualitative descriptive study included 12 individuals of 10 rural clubs affiliated with the South Australian National Football League. Recruitment occurred via emails to club secretaries/presidents. Semi-structured telephone interviews explored mental health and wellbeing issues experienced in clubs, previous involvement with mental wellbeing programs, and potential barriers/enablers for future programs. Interviews were transcribed verbatim and analysed thematically. Thematic analysis identified three themes encompassing barriers and enablers: (1) more than a football club, (2) attitudes towards mental health, and (3) what is needed to implement a program. The third theme had subthemes of resources, importance of timing, mental health initiatives and components of a program. Key barriers included difficulty getting people involved due to individual attitudes towards mental health, and not having the finances/resources to implement a program. Major enablers included the important role the football club serves in the community, the inclusion of speakers with credibility, and making the program engaging. SO WHAT?: This study identifies key factors which may impact on community engagement and program effectiveness for mental health and wellbeing programs delivered via rural football clubs.

#5 Heart rate variability and pre-competitive anxiety according to the demanding level of the match in female soccer athletes
Reference: Physiol Behav. 2020 May 11:112926. doi: 10.1016/j.physbeh.2020.112926. [Epub ahead of print]
Authors: Ayuso-Moreno RM, Fuentes-García JP, Collado-Mateo D, Villafaina S
Summary: The present study aimed to evaluate the effects of a highly-demanding match and a lowly-demanding match on pre-competitive heart rate variability (HRV) and anxiety in semi-professional female soccer athletes. A total of 14 players, with a mean age of 23.78 (4.93), from the Cáceres Women Football Club of the Spanish Second National Division participated in our study. They were evaluated in two microcycles which correspond to a highly- and a lowly-demanding matches. For each microcycle a baseline and a pre-competitive measures were collected. Results indicated that HRV was significantly reduced before a highly demanding match whereas a lowly-demanding match did not lead to any change. Significant differences in HRV and cognitive anxiety were observed when compared the highly and the lowly demanding matches, which means an increase in the anxiety levels before the highly-demanding match. HRV could be an indicator of precompetitive anxiety in semi-professional female soccer players. This could be used by coaches or physical trainers as a tool to examine the precompetitive anxiety in athletes.

#6 The Increased Effectiveness of Resistance Training on Unstable vs. Stable Surfaces on Selected Measures of Physical Performance in Young Male Soccer Players
Reference: J Strength Cond Res. 2020 May 13. doi: 10.1519/JSC.0000000000003590. [Epub ahead of print]
Authors: Sanchez-Sanchez J, Raya-González J, Ramirez-Campillo R, Chaabene H, Petisco C, Nakamura FY
Summary: The purpose was to examine the effects of 10-week (2/wk) resistance training on stable vs. unstable surfaces on selected measures of physical performance in young male soccer players, national-level U19 players participated in this study. They were randomly allocated to an unstable resistance training group (uRT, n = 27) or a stable resistance training group (sRT, n = 28). Before and after the training, horizontal jumping with dominant (Hop D) and nondominant leg (Hop non-D), repeated sprint ability (RSA best time [RSAbest] and RSA mean time [RSAmean]), change-of-direction (COD) speed (Illinois COD test), and aerobic endurance (YoYo Intermittent Recovery Test Level 1 [YoYo IR1]) were assessed. To establish the effects of the interventions on the dependent variables, a 2 (group: uRT and sRT) × 2 (time: pre, post) analysis of variance with repeated measures on time was computed. A significant main effect of time was observed for Hop non-D, RSAbest, and RSAmean (p = 0.003-0.06, effect size [ES] = 0.06-0.15). Furthermore, significant group × time interactions were shown for RSAbest (p = 0.007, ES = 0.13) and RSAmean (p = 0.002, ES = 0.2). Post hoc analysis revealed significant pre- to post-training improvements for RSAbest (p = 0.002, ES = 0.35) and RSAmean (p = 0.0002, ES = 0.36) in the uRT. In the sRT, however, no significant pre-post performance changes were observed in RSAbest and RSAmean. In conclusion, 10 weeks of an in-season resistance training on unstable conditions in addition to regular soccer training was effective in improving repeated-sprint ability performance in youth male elite soccer players including maximal linear sprinting and the ability to perform repeated sprint.

#7 How and why do young soccer players change the Flow State?
Reference: PLoS One. 2020 May 14;15(5):e0233002. doi: 10.1371/journal.pone.0233002. eCollection 2020.
Authors: Castillo-Rodríguez A, Lopera CU, Onetti-Onetti W, Chinchilla-Minguet JL
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Summary: Flow State (FS) as well as other psychological characteristics influence sports performance (SP) and could be relevant according to the playing position in team sports, such as the soccer where players have different specific functions within the team. The aim of this study was to evaluate the difference in FS dimensions in young soccer players between training time (TR) and official competition time (CM), according to the playing position and, to find relationships between FS dimensions and physical characteristics and academic performance. A total of 141 U16 soccer players were selected (14.7 ± 0.5 years). Data was collected for academic performance, physical and socio-demographic characteristics, and on two occasions, the dimensions of FS (before of a TR and CM). The results showed that the FS dimensions are higher before of the TR than before of the CM (p < 0.05) in all playing positions. In clear goals dimension, forwards showed lower scores than other playing positions, and various dimensions had a positive relationship with academic performance. In conclusion, the FS presented in CM is lower in U16 soccer players compared to that presented in TR. This work has contributed to increasing the knowledge of the fluctuation of the FS that negatively influence the soccer player in pre-competition states and the influence of various factors on this construct.

#8 Does the FIFA 11+ Program Prevent Hamstring Injuries in College-Aged Male Soccer Players? A Critically Appraised Topic
Reference: J Sport Rehabil. 2020 May 13:1-3. doi: 10.1123/jsr.2019-0390. [Epub ahead of print]
Authors: Street SB, Kaminski T.
Summary: Hamstring injuries are the most prevalent lower-extremity injury among soccer players. The Fédération Internationale de Football Association (FIFA) has addressed this issue by developing the FIFA 11+ program, which is focused on improving strength and decreasing the incidence of lower-extremity injuries in the sport. This critically appraised topic focuses on this program as well as one of its components, the Nordic hamstring exercise, in the prevention of hamstring injuries. Clinical Question: Does the FIFA 11+ program prevent hamstring injuries in college-aged male soccer players? Summary of Key Findings: Four studies were selected to be critically appraised. The PEDro checklist was used to score the articles on methodology and consistency. All 4 articles demonstrated support for the clinical question. Clinical Bottom Line: There is moderate evidence to support the use of the FIFA 11+ program and Nordic hamstring exercise as part of a college soccer team's warm-up routine. Strength of Recommendation: Grade B evidence exists in support of incorporating the FIFA 11+ program to reduce the incidence of hamstring injuries in male college soccer players.

#9 HIV knowledge, risky behaviours and public health care services attendance among adolescents from the Grassroot soccer Zimbabwe programme
Reference: BMC Health Serv Res. 2020 May 13;20(1):420. doi: 10.1186/s12913-020-05305-3.
Authors: Mzingwane ML, Mavondo GA, Mantula F, Mapfumo C, Gwatiringa C, Moyo B, Dube P, Chaibva CN
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Summary: Interventions aimed at improving accessing of health care services, including HIV testing, remain a priority in global HIV eradication efforts. Grassroot Soccer Zimbabwe (GRSZ) is an adolescent health organisation that uses the popularity of soccer to promote healthy behaviours. We assessed HIV knowledge levels, risky behaviours and attitudes in school going adolescents and young adults who attended GRSZ programmes and determined if HIV knowledge levels were associated with increased levels of accessing of health care services by youths. This was a cross-sectional study carried out on 450 participants aged 13-30 years who attended at least one of the three programmes offered by GRSZ. Self-administered and self-reporting questionnaires were used to collect information on participants' demographics, knowledge on HIV and reproductive health, sources of information, access to HIV and reproductive health services and attitudes and risky behaviours. A total of 392 (87.1%) responses were received. High HIV and reproductive health knowledge levels were recorded (77.7%) on our scale with females recording higher levels (81.1%) than males (71.1%). The majority of participants (72%) indicated willingness to abstain from risky behaviours such as use of drugs and attending youth sex parties. However about 33.3% of the participants who had sexual intercourse reported having condomless sex. There was marginal association between high HIV and reproductive health knowledge levels and accessing health care services in the past 24 months (p = 0.045). HIV and reproductive health knowledge levels were relatively high among adolescents and were associated with accessing health care services in the past 24 months. There however are some gaps associated with engaging in risky sexual behaviours such as condomless sex which could be addressed by using these findings to assist organizations working with adolescents, educators and policy makers in developing programmes that address adolescent sexual behaviours.

#10 Effects of Age and Maturation on Lower Extremity Range of Motion in Male Youth Soccer Players
Reference: J Strength Cond Res. 2020 May 8. doi: 10.1519/JSC.0000000000003642. [Epub ahead of print]
Authors: Robles-Palazón FJ, Ayala F, Cejudo A, De Ste Croix M, Sainz de Baranda P, Santonja F
Summary: Restricted joint range of motion (ROM) has been considered as a primary risk factor for some sport-related injuries. Consequently, preparticipation assessment of lower extremity joints ROM could help identify youth soccer players at high risk of injury and to aid in the design of tailored age and maturational specific training interventions. The purpose of this study was to analyze and compare the influence of chronological age and maturational stage on several lower extremity ROM measures, as well as to describe the lower extremity ROM profile using a comprehensive approach in youth soccer players. A total of 286 male youth soccer players' ROM were assessed including passive hip (extension [PHE], adduction with hip flexed 90° [PHADHF90°], flexion with knee flexed [PHFKF] and extended [PHFKE], abduction with hip neutral [PHABD] and flexed 90° [PHABDHF90°], external [PHER] and internal [PHIR] rotation), knee (flexion [PKF]) and ankle (dorsiflexion with knee flexed [ADFKF] and extended [ADFKE]) ROMs. Between-group differences were analyzed using a one-way analysis of variance (ANOVA) and magnitude-based decisions. The results only report statistically significant (p < 0.05; d > 0.5) and clinically relevant differences (>8°) for the PKF ROM between U12 vs. U19, and Pre-PHV vs. Post-PHV groups. Furthermore, approximately 40, 35, and 20% of players displayed restrictions in their PHFKE, PKF, and ADFKF ROM values, respectively. These findings emphasize the necessity of prescribing (across all age groups and periods of growth and maturation) compensatory measures in daily soccer training, and these exercises should be equally applied to both limbs with the aim of improving PHFKE, PKF and ADFKF ROM values.

#11 Bio-banding in junior soccer players: a pilot study
Reference: BMC Res Notes. 2020 May 12;13(1):240. doi: 10.1186/s13104-020-05083-5.
Authors: Romann M, Lüdin D, Born DP
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Summary: Bio-banding (BB) has been introduced to account for varying maturity and to improve the talent development of junior soccer players. To date, research that investigated the physiological and technical effects of BB is sparse. Therefore, the aim of the study was to compare effects of BB with CA on selected technical and tactical parameters in U13 and U14 soccer players. BB significantly increased the number of duels (p = 0.024) and set pieces (p = 0.025) compared to chronological age. The mean time of ball possession per action was reduced (p = 0.021) and the rate of successful passes was lower with BB (p = 0.001). Meanwhile, the total number of passes was unaffected (p = 0.796), and there was a trend towards a lower difference in ball possession between BB teams (p = 0.058). In addition, BB reduced the distances covered while jogging (p = 0.001), running (p = 0.038) and high-speed running (p = 0.035). With BB, an increased number of duels, unsuccessful passes and set pieces resulted in a quicker change of match play situations between teams. While physical demand was reduced, BB seems to result in a more technically and tactically challenging game. Benefits in long-term player development, however, require further investigation.

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