Latest research in football - week 35 - 2014

Latest research in football

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

Following studies were retrieved for this week:


#1 Corporate social responsibility and mental health: The Premier League football Imagine Your Goals programme
Reference: Int Rev Psychiatry. 2014 Aug;26(4):460-6. doi: 10.3109/09540261.2014.924486.
Authors: Henderson C, O'Hara S, Thornicroft G, Webber M.
Summary: Football is increasingly used to facilitate recovery in mental health services, often in partnership with football clubs. However, few clubs have made mental health part of their corporate social responsibility programmes until recently. We report the impact on participants of the 'Imagine Your Goals' programme, run by 16 Premier League football clubs in conjunction with England's Time to Change programme to reduce mental health-related stigma and discrimination. Mixed methods evaluation used pre/post measures of well-being, access to social capital, focus groups held early on and towards the end of the two-year programmes, and questionnaires for coaching staff. There were no significant changes to participants' mental well-being scores between baseline and follow-up, nor to the total number of social resources accessible through their networks. However, there was a statistically significant increase at follow-up in the mean score of the personal skills subscale of the Resource Generator-UK. Participants' individual skills were also higher at follow-up. Qualitative data showed programmes had largely met participants' expectations in terms of socializing, providing structure and improving fitness levels, exceeded expectations in relationships with coaching staff and additional activities, but did not always meet them in improving football skills. Participants varied in their knowledge of exit opportunities, depending on which club's programme they attended. A minority of clubs reported difficulties in recruitment and concerns about planning for the future of the projects. Football clubs and the charitable foundations they set up can successfully deliver programmes to people with mental health problems which improve access to personal skills social capital and have other potential benefits.

#2 Effect of Birth Month on Physical Fitness of Soccer Players (Under-15) According to Biological Maturity
Reference: Int J Sports Med. 2014 Aug 21. [Epub ahead of print]
Authors: Fragoso I, Massuca LM, Ferreira J
Summary: This study aims to clarify the relationship between the birth quarters, biological maturity and physical fitness (PF) in Under-15 youth soccer players. Each participant (n=133) was an Under-15 player from a top-elite soccer academy. The data collection period lasted 8 years (from Under-15 2002/2003 to 2009/2010 season). The athletes' birth dates were recorded and organized by birth quarters (Q1, first; Q2, second; Q3, third; Q4, fourth) and by semesters (S1, first; S2, second). Additionally recorded were each athlete's biological maturity (skeletal age, SA), anthropometric profile (stature; body mass; thigh, calf and upper arm girths), and fitness profile (10-m and 30-m sprint times; SJ; CMJ; shuttles in YYIR Test). Significant differences were found for (1) decimal age and SA by quarters (Q4-Q1, Q2) and semesters; and (2) stature (Q3-Q1, Q2, Q4; S1-S2), body mass (Q1-Q3; S1-S2), thigh girth (S1-S2), SJ (Q1-Q2) and sprint time (Q4-Q1, Q2; S1-S2). When maturity was considered as covariate all PF variables, with exception of SJ (Q1-Q2) and 10-m sprint time (S1-S2), were very similar among the studied groups. These findings suggest that (1) seasonal birth effect may result from the observed biological maturation differences, and (2) athletes may have been chosen due to their PF attributes.

#3 Relationship between Nutrition Knowledge and Physical Fitness in Semiprofessional Soccer Players
Reference: Scientifica (Cairo). 2014;2014:180353. doi: 10.1155/2014/180353. Epub 2014 Jul 21.
Authors: Nikolaidis PT, Theodoropoulou E
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Summary: Whereas nutrition has a crucial role on sport performance, it is not clear to what extent nutrition knowledge is associated with physical fitness. The aim of this study was to examine the current level of nutrition knowledge of soccer players and whether this level is associated with physical fitness. Soccer players (n = 185, aged 21.3 ± 4.9 yr, weight 72.3 ± 8.4 kg, and height 177.5 ± 6.4 cm) performed a battery of physical fitness tests (sit-and-reach test, SAR; physical working capacity in heart rate 170, PWC170; and Wingate anaerobic test, WAnT) and completed an 11-item nutrition knowledge questionnaire (NKQ). Low to moderate Pearson correlations (0.15 < r < 0.34, p < 0.05) of NKQ with age, weight, height, fat free mass (FFM), SAR, peak power, and mean power of WAnT were observed. Soccer players with high score in NKQ were older (4.4 yr (2.2; 6.6), mean difference (95% confidence intervals)) and heavier (4.5 kg (0.6; 8.3)) with higher FFM (4.0 kg (1.1; 6.8)) and peak power (59 W (2; 116)) than their counterparts with low score. The moderate score in the NKQ suggests that soccer players should be targeted for nutrition education. Although the association between NKQ and physical fitness was low to moderate, there were indications that better nutrition knowledge might result in higher physical fitness and, consequently, soccer performance.

#4 Comparison of the immediate effect of different types of trunk exercise on the star excursion balance test in male adolescent soccer players
Reference: Int J Sports Phys Ther. 2014 Aug;9(4):428-35.
Authors: Imai A, Kaneoka K, Okubo Y, Shiraki H
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Summary: Trunk exercises, such as trunk stabilization exercises (SE) and conventional trunk exercises (CE), are performed to improve static or dynamic balance. Recently, trunk exercises have also been often used as part of warm-up programs. A few studies have demonstrated the immediate effects of SE and CE on static balance. However, immediate effects on dynamic balance are not yet known. Therefore, the purpose of this study was to compare the immediate effect of SE with that of CE on the Star Excursion Balance Test (SEBT). Eleven adolescent male soccer players (17.9 ± 0.3 years, 168.5 ± 5.4 cm, and 60.1 ± 5.1 kg) participated in this study. A crossover design was used, and each participant completed three kinds of testing sessions: SE, CE, and non-exercise (NE). Experiments took place for three weeks with three testing sessions, and a 1-week interval was provided between different conditions. Each testing session consisted of three steps: pretest, intervention, and posttest. To assess dynamic balance, the SEBT score in the anterior, posteromedial, and posterolateral directions was measured before and 5 minutes after each intervention program. The data of reach distance were normalized with the leg length to exclude the influence of the leg length on the analysis. The SEBT composite score was significantly improved after the SE (p < 0.05) but did not change after the CE and NE (p > 0.05). Furthermore, in the SE condition, SEBT scores of the posterolateral and posteromedial directions were significantly improved at the posttest, compared with those at the pretest (p < 0.05). This study demonstrated the immediate improvements in the posteromedial and posterolateral directions of the SEBT only after the SE. This result suggests that the SE used in this study is effective in immediately improving dynamic balance.

#5 Finale furioso: referee-biased injury times and their effects on home advantage in football
Reference: J Sports Sci. 2014 Aug 21:1-10. [Epub ahead of print]
Authors: Riedl D, Strauss B, Heuer A, Rubner O.
Summary:  The role of referees has become a central issue in the investigation of home advantage. The main aim of this study was a thorough examination of the referee bias concerning injury time in football, which is currently seen as an important example for the assertion that referees contribute to home advantage. First, we use archival data from the German Bundesliga (seasons 2000/2001-2010/2011) to confirm the existence of an asymmetry in the allocation of injury time. We show this asymmetry to be a bias by ruling out hitherto remaining alternative explanations (effect = 18 s, P < 0.001, [Formula: see text] = 0.05). Second, we identify a further referee bias, stating that referees systematically accord more injury time when one team leads in the game compared to a draw (effect = 21 s, P = 0.004, [Formula: see text] = 0.06). Third, the quantitative benefit of home or away teams in goals and points due to these biases is assessed. Overall, referee decisions on injury time indeed reveal biases, but they do not contribute to the home advantage, that is, there is no significant effect on goals scored by the teams. The qualitative findings (a new bias on injury time) as well as the quantitative findings (no overall effect) shed new light on the role of referees for home advantage.

#6 The diagnostic and prognostic value of ultrasonography in soccer players with acute hamstring injuries
Reference: Am J Sports Med. 2014 Feb;42(2):399-404. doi: 10.1177/0363546513512779. Epub 2013 Dec 11.
Authors: Petersen J, Thorborg K, Nielsen MB, Skjødt T, Bolvig L, Bang N, Hölmich P.
Summary: An injury to the hamstring muscle complex is the most common injury in soccer. Ultrasound of acute hamstring injuries is often used as a clinical tool for diagnosing hamstring injuries and guiding players in when they can return to play. To (1) investigate the characteristic sonographic findings of acute hamstring injuries in soccer players, (2) compare the mean injury severity (time to return to play) in injured players with and without sonographically verified abnormalities, and (3) correlate the length of the injured area and absence from soccer play (time to return to play) to investigate if ultrasonography can be used as a prognostic indicator of time to return to play. Players from 50 teams participating in 1 of the top 5 Danish soccer divisions were followed in the period from January to December 2008. Of 67 players with acute hamstring injuries, 51 underwent ultrasonographic examination of the injured thigh and were included in this study. Ultrasonographic examinations were performed 1 to 10 days after injury (mean, 5.2 ± 3.0 days), and sonographic findings were present in 31 of 51 cases (61%). Two thirds of the injuries were to the biceps femoris muscle and one third to the semitendinosus muscle. No total ruptures were documented. The 51 acute hamstring injuries resulted in absence from soccer of a mean 25.4 ± 15.7 days per injury, with no significant difference between players with and without sonographically verified abnormalities (P = .41). No correlation existed between the length of the injured area and injury severity (r = 0.19, P = .29). The biceps femoris is the most commonly injured hamstring muscle detected by ultrasound, and more than half of the injuries are intramuscular. Because neither the presence of sonographic findings nor the size of the findings was correlated with time to return to play in injured soccer players, the prognosis of hamstring injuries should not be guided by these findings alone.

#7 Practice and play as determinants of self-determined motivation in youth soccer players
Reference: J Sports Sci. 2014;32(11):1091-9. doi: 10.1080/02640414.2014.880792. Epub 2014 Jan 30.
Authors: Hendry DT, Crocker PR, Hodges NJ
Summary: Based upon predictions derived from the Developmental Model of Sports Participation, we tested whether hours in domain-specific play (self-led activities) and practice (coach-led activities) during childhood (~5-12 year) in an elite group of youth soccer players from the UK (N = 144) were related to motivation. Independent analysis of three different age groups (Under 13, 15 and 17 year) did not show relations between play and practice activities during childhood and global measures of motivation. However, secondary analysis showed that when controlling for years in soccer, years in the UK Academy system were negatively related to global indices of self-determined motivation (SDI) and positively related to controlled motivation for the oldest players. Despite predictions, there was no evidence that play during childhood was positively related to more SDI. Prospective research is recommended to enable more robust conclusions about the role of early developmental practice activities, especially early specialisation in a high-performance system, on both skill and psychosocial development.

#8 Sport events and climate for visitors-the case of FIFA World Cup in Qatar 2022
Reference: Int J Biometeorol. 2014 Aug 14. [Epub ahead of print]
Authors: Matzarakis A, Fröhlich D.
Summary: The effect of weather on sport events is not well studied. It requires special attention if the event is taking place at a time and place with extreme weather situations. For the world soccer championship in Qatar (Doha 2022), human biometeorological analysis has been performed in order to identify the time of the year that is most suitable in terms of thermal comfort for visitors attending the event. The analysis is based on thermal indices like Physiologically Equivalent Temperature (PET). The results show that this kind of event may be not appropriate for visitors, if it is placed during months with extreme conditions. For Doha, this is the period from May to September, when conditions during a large majority of hours of the day cause strong heat stress for the visitors. A more appropriate time would be the months November to February, when thermally comfortable conditions are much more frequent. The methods applied here can quantify the thermal conditions and show limitations and possibilities for specific events and locations.


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