Latest research in football - week 8 - 2013

#1 VO2 max Characteristics of Male Professional Soccer Players 1989-2012
Authors: Tønnessen E, Hem E, Leirstein S, Haugen T, Seiler S
Reference: Int J Sports Physiol Perform. 2013 Feb 14.
Summary: The purpose of this investigation was to quantify VO2max performance in soccer as a function of performance level, position, age and time of season. Additionally, the authors examined the evolution of VO2 max among professional players over a longitudinal period of 23 year. One-thousand-five-hundred- and-forty-five male soccer players tested VO2max at the Norwegian Olympic Training Center between 1989 and 2012. The results showed no differences in VO2max between national team players, 1st - 2nd division players and juniors. However, midfielders had higher VO2max than defenders, forwards and goalkeepers. Players aged below 18 years of age had approximately 3% significant higher VO2max than players aged 23-26 years. Generally, the players had 1.6 and 2.1% significant lower VO2max during off season compared to pre season and in season (p=0.021), respectively. The VO2max relative to body among the professional players did not improve over time. The study provides effect magnitude estimates for the influence of performance level, player position, age, and season time on VO2max in male elite soccer. The authors also concluded that a VO2max values ~ 62-64 mL/min/kg body weight fulfill the demands for aerobic capacity in male professional soccer and furthermore, VO2max is not a clearly distinguishing variable separating players of different standard.


#2 Cognitive strategies for goalkeeper responding to soccer penalty kick
Authors: Peiyong Z, Inomata K.
Reference: Percept Mot Skills. 2012 Dec;115(3):969-83.
Summary: The purpose of the study was to examine how a goalkeeper's response-initiation time influences the accuracy of the response to a soccer penalty kick. Twenty-four (12 experienced soccer goalkeepers, and 12 experienced soccer field players) university male students participated in this study. The players were required to watch videos made by three different kickers preparing a penalty kick. Twelve ensuing moments, occluded 467 msec. before impact of the kicker's foot with the ball to 267 msec. after impact for three different kicks (instep, front of foot, inside of foot) directed at three different possible positions within the goal (left, right, center). The players were required to move their body to intercept the oncoming ball. The results showed that none of the groups (goalkeepers'  and field players )could use the advance visual cues to anticipate the direction of the ball, when they initiated a response before the moment of impact during the penalty kick. However, all groups were successful when the response was initiated after impact. In comparison to the field players, the goalkeepers' group had a significantly faster response-initiation time, which leaded to the conclusion that the goalkeepers were more likely to adopt a strategy of relying on situational probabilities in situations where the speed of response is critical.


#3 Comparison of Hamstring Strain Injury Rates Between Male and Female Intercollegiate Soccer Athletes
Authors: Cross KM, Gurka KK, Saliba S, Conaway M, Hertel J.
Reference: Am J Sports Med. 2013 Feb 13.
Summary: The purpose of the study was to compare the hamstring strain injury rates in event and athlete characteristics between male and female college soccer athletes. Data regarding partial and complete hamstring strains were obtained from the National Collegiate Athletic Association (NCAA) Injury Surveillance System (ISS) for men's and women's soccer from 2004 to 2009. Data were evaluated comparing the incidence of hamstring strains between the sexes as well as during games versus practices and the preseason versus the in-season were calculated. The data showed that male players had a greater 64% chance to sustain a hamstring strain. The injury rates were significantly greater for men during practice and game. However, there was no difference between gender for injury rates during the preseason, however, men were significantly more likely to sustain a hamstring strain during the in-season. Women had significantly less recurrent hamstring strains.


#4 Psychological predictors of injury occurrence: a prospective investigation of professional Swedish soccer players
Authors: Ivarsson A, Johnson U, Podlog L.
Reference: J Sport Rehabil. 2013 Feb;22(1):19-26.
Summary: The purpose of the study was evaluate whether personality, stress, and coping predicted injury occurrence in an elite soccer population based on a hypothesized model. Fifty-six (38 male, 18 female) Swedish Premiere League soccer players were selected based on convenience sampling. All participants completed different four different questionnaires. The first three (1. Swedish Universities Scales of Personality, 2. Life Events Survey for Collegiate Athletes, 3. COPE) were completed once and the Hassle and Uplift Scale5 were submitted once/week for a 13-week period throughout the competitive season. A path analysis was conducted examining the influence of personality traits (such as trait, anxiety), state-level stressors (such as negative-life-event stress), and coping on injury frequency. The results indicated that trait anxiety, negative-life-event stress, and daily hassle were significant predictors of injury among professional soccer players. The predictors accounted for 24% of the variance, which lead the authors to the conclusion that athletes, coaches, and medical practitioners should attempt to reduce state-level stressors, especially daily hassles, in minimizing injury risk.


#5 Neural bases for anticipation skill in soccer: an FMRI study
Authors: Bishop DT, Wright MJ, Jackson RC, Abernethy B.
Reference: J Sport Exerc Psychol. 2013 Feb;35(1):98-109.

Summary: The purpose of the study was to examine the neural bases for perceptual-cognitive superiority in a soccer anticipation task using functional magnetic resonance imaging (fMRI). Whilst predicting an oncoming opponent's movements via video-based, thirty-nine participants were investigated via an MRI. Video clips were occluded at four time points, and participants were grouped according to in-task performance. Early occlusion reduced prediction accuracy significantly for all participants, as did the opponent's execution of a deceptive maneuver, but high-skill participants were significantly more accurate than their low-skill players under deceptive conditions. The significant better results between the participants in different skill groups in perceptual-cognitive performance was associated with greater activation of cortical and subcortical structures involved in executive function and oculomotor control.


#6 Perfectionism and Burnout in Junior Soccer Players: A Test of the 2 x 2 Model of Dispositional Perfectionism
Author: Hill AP
Reference:  J Sport Exerc Psychol. 2013 Feb;35(1):18-29.
Summary: The purpose of the study was to investigate the interactive effects of dimensions of perfectionism in predicting symptoms of athlete burnout. Junior male soccer players (N=167) from English professional soccer clubs participated in this study completed paper-and-pencil measures of perfectionism and symptoms of athlete burnout. The previously provided 2 × 2 model may offer a useful framework through which to explain the interactive effects of dimensions of perfectionism on athlete burnout.