Latest research in football - week 47 -2022

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 Change of direction frequency off the ball: new perspectives in elite youth soccer

Reference: Sci Med Footb. 2022 Nov;6(4):473-482. doi: 10.1080/24733938.2021.1986635. Epub 2021 Oct 4.

Authors: Oliver J Morgan, Barry Drust, Jack D Ade, Mark A Robinson

Summary: The aim of this study was to investigate the frequency of change of directions (COD) and examine the influences of position, leg dominance and anthropometrics on COD in elite youth soccer match play. Twenty-four elite male English Premier League (EPL) academy players (19.0 ± 1.9 years) were individually recorded during ten competitive U18s and U23s matches. Video footage of individual players was analysed using a manual notation system to record COD frequency, direction, estimated angle and recovery time. The influences of position, anthropometrics and leg dominance were accounted for. Elite youth soccer players performed on average 305 ± 50 CODs with on average 19.2 ± 3.9 seconds of recovery. The frequency of CODs was independent of position, leg dominance, anthropometry and occurred equally between left and right direction and forwards and backwards direction. CODs were mostly ≤90° (77%) and there were significantly less CODs in the 2nd half (-29, ES = 1.23, P< 0.001). The average and peak within match demands within 15 and 5-minute periods were 49 and 62 CODs, and 16 and 25 CODs, respectively. This study is the first to illustrate COD frequencies of elite youth soccer match play, providing practitioners guidance to prepare soccer players for competitive match demands.



#2 An intervention plan for preventing and handling amateur soccer players' injuries

Reference: Niger J Clin Pract. 2022 Nov;25(11):1816-1822. doi: 10.4103/njcp.njcp_237_22.

Authors: M A Bakarman, M Tashkandi, N S Mohammed

Summary: The majority of amateur soccer players are vulnerable to soccer-related injuries and many such injuries are avoidable with an adequate education. The present study aimed to measure the impact of an intervention educational plan on improving amateur soccer players' knowledge and skills in preventing and handling soccer-related injuries. The study design is a group-clustered randomized intervention-control trial, and it was carried out in Taif city, Saudi Arabia. The "Neighborhood League of Football" players were randomly allocated to a soccer injury prevention education group (intervention group) and a control group. A predesigned and validated questionnaire was used to study the changes in knowledge and skills about soccer injuries before the intervention (response a) and after (response b). The study included 246 participants in the intervention group and 256 in the control group (n = 502). The median age was 22 years. The comparison of both groups' participants' performance showed significant differences in response b analyses and participants in the intervention group achieved significantly higher scores than the control group in total score levels (P < .0001), injury mechanisms (P < .0001), injury treatment and prevention (P < .0001), and health status (P < .034). The intervention group's scores on response b (after the educational sessions) were significantly higher than response a (before the educational sessions, P < 0.001). In multiple scales and overall score levels, intervention group participants achieved significantly higher scores than their control group counterparts. Educational assistance appears to have had a good impact on their knowledge and skills.



#3 Player Sex and Playing Surface Are Individual Predictors of Injuries in Professional Soccer Players

Reference: Pathophysiology. 2022 Oct 26;29(4):619-630. doi: 10.3390/pathophysiology29040048.

Authors: Zakariya H Nawasreh, Mohammad A Yabroudi, Ahmad A Darwish, Wesam A Debes, Khaldoon M Bashaireh

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Summary: The factors contributing to soccer injuries and their influence on the occurrence of injury are controversial and inconclusive. This study aimed to determine the association between player characteristics and playing factors with injuries in professional soccer players. One hundred and fifty-two professional soccer players completed a self-administered questionnaire that asked about demographic information and injury profile, the type of playing surface on which they sustained their injury, medical treatment, and the time lost due to soccer injury at the end of the soccer season. The injury rate was 44.74% (n = 68; males: 61.50% (n = 56), females: 19.70% (n = 12)). Players' age (OR: 1.15, 95%CI: 1.05-1.25, p &lt; 0.002) and BMI (OR: 1.21, 95%CI: 1.06-1.38, p &lt; 0.003) were significantly associated with soccer injuries. After adjusting for age and BMI, players' sex (OR: 5.39, 95%CI: 2.11-13.75, p &lt; 0.001), previous soccer injury (OR: 3.308, 95%CI: 2.307-29.920, p &lt; 0.001), and playing surfaces (OR: 11.07, 95%CI: 4.53-27.03, p &lt; 0.001) were the significant predictors of soccer injuries. Players' age, BMI, sex, previous soccer injury, and playing surface were associated with injuries among professional soccer players. Old male athletes with high BMI, previous soccer injuries, and playing on natural grass were more likely to sustain soccer injuries than young female players with low BMI who had no previous injuries and played on synthetic surfaces.



#4 The mid-term effect of Osgood-Schlatter disease on knee function in young players from elite soccer academies

Reference: Phys Sportsmed. 2022 Nov 22;1-6. doi: 10.1080/00913847.2022.2148492. Online ahead of print.

Authors: E Bezuglov, B Pirmakhanov, G Ussatayeva, A Emanov, Yu Valova, A Kletsovskiy, V Khaitin, E Usmanova, M Butovskiy, R Morgans

Summary: The aim of the study was to evaluate the effect of Osgood-Schlatter disease (OSD) on knee joint function in elite young soccer players. Our hypothesis was that knee joint function in elite young soccer players was impaired following OSD compared with soccer players with no history of OSD. In young male soccer players (n = 36) from elite academies (mean ±SD, age: age: 15,3 ± 1,7 years; height: 1,7 ± 0,06 m; weight: 63,5 ± 8 kg; BMI: 20,7 ± 2). The duration between the completion of treatment or the last complaint to the study commencement was 31 ± 19 months. The average treatment duration of OSD among study participants was 18,5 ± 12 days (95%, 14-23), and the disease most often manifested in winter and spring, 33% and 31% of cases, respectively. Soccer players with a history of OSD were statistically different in IKDC and KOOS scores when compared with soccer players with no previously reported OSD (Mann-Whitney, p < 0,0001). The soccer players with a history of OSD also use NSAIDs more frequently compared with soccer players with no history of OSD (36% vs 3% respectively). OSD among young soccer players, when symptoms resolve, continue about one month and they can return to regular training and participation in games. Wherein, the negative effects in knee joint function were significantly more likely in soccer players with previous OSD history when compared with their peers with no history of OSD. While oral non-steroidal anti-inflammatory drugs was also more widely employed in soccer players with previous OSD history. Potentially this may lead to performance deficits and disadvantages for their future careers and coaches and physicians should be informed.



#5 Maturation Stage Does Not Affect Change of Direction Asymmetries in Young Soccer Players

Reference: J Strength Cond Res. 2022 Dec 1;36(12):3440-3445. doi: 10.1519/JSC.0000000000004110. Epub 2021 Oct 7.

Authors: Nikolaos D Asimakidis, Athanasios A Dalamitros, João Ribeiro, Afroditi C Lola, Vasiliki Manou

Summary: This study examined whether the stage of biological maturation can affect interlimb asymmetries during a change of direction (COD) test. Seventy-six young soccer players were divided into 2 different groups according to their peak height velocity stage (PHV): pre-PHV (n = 45, age = 11.8 ± 1.2 years, height = 149.8 ± 9.3 cm, body mass = 43.9 ± 11.2 kg) and post-PHV (n = 31, age = 14.4 ± 0.9 years, height = 170.0 ± 4.9 cm, body mass = 61.5 ± 8.9 kg). Subjects performed a 505 test to measure the completion time in both directions and a 20-m maximum sprint test. Change of direction deficit (CODD) was used as a measure for isolating COD ability. An independent sample t-test detected no significant differences between the asymmetry index values for the 505 test completion time when the pre-PHV group and the post-PHV group were compared (-3.49 ± 2.49% vs. -3.45 ± 2.47%, effect size [ES] = 0.02, p = 0.923). Similarly, the CODD asymmetry index indicated no differences between the 2 groups (-8.21 ± 5.95% vs. -7.37 ± 5.12%, ES = 0.15, p = 0.457). A paired sample t-test revealed that the values of the CODD asymmetry index were larger than those of the 505 asymmetry index (-7.88 ± 5.61% vs. -3.49 ± 2.46%, ES = 1.09, p < 0.001). According to these results, maturational status has no influence on the interlimb asymmetries of COD ability. Furthermore, subjects showed greater asymmetry values in CODD compared with the 505 test completion time, reinforcing that the evaluation of COD asymmetries should be based on CODD. As interlimb asymmetries are not altered during the maturation process, practitioners should address abnormal COD asymmetries early on during athletes' development processes.



#6 Effects of a small-sided games training program in youth male soccer players: variations of the locomotor profile while interacting with baseline level and with the accumulated load

Reference: BMC Sports Sci Med Rehabil. 2022 Nov 23;14(1):198. doi: 10.1186/s13102-022-00595-y.

Authors: Ana Filipa Silva, Rafael Oliveira, Halil Ibrahim Ceylan, Zeki Akyildiz, Francisco Tomás González-Fernández, Hadi Nobari, Mehmet Yıldız, Sabri Birlik, Filipe Manuel Clemente

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Summary: This study aimed to (1) analyze the impact of a small-sided game training program in the locomotor profile of youth male soccer players (while interacting with the baseline level - higher and lower level); and (2) test the relationships between variation in locomotor profile and the accumulated demands in 3v3, 5v5 and match over the period of observation. The cohort lasted 3-weeks. Twenty under-17 male amateur soccer players (16.8 ± 0.41 years; experience: 6.35 ± 0.67 years) were assessed twice for their final velocity at 30-15 intermittent fitness test (VIFT), peak speed at 30-m sprint test (PSS) and anaerobic speed reserve (ASR). The PSS was estimated using a Global Positioning System, while the VIFT was estimated using the maximum level attained by the players during the test. Based on the baseline levels, the scores were standardized using the Z-score. The total score of athleticism (TSA) was calculated per player to organize the players into two groups: lower TSA and higher TSA. Over the three weeks of observation, the small-sided games of 3v3 and 5v5 and match demands were monitored using polar team pro. The heart rate responses (mean and peak), distance covered (overall and split by speed thresholds), and peak speed in these games were obtained and summed over the weeks. The repeated measures ANCOVA tested the variations (time) of the locomotor profile of players while considering the baseline as covariable and the group as a factor. The Pearson-product correlation test analyzed the relationships between variations in locomotor profile (Δ, post-baseline) and the accumulated demands in 3v3, 5v5, and match. Between-groups analysis (lower TSA vs. higher TSA) revealed no significant differences on VIFT (p = 0.915), PSS (p = 0.269), ASR (p = 0.258) and TSA score (p = 0.138). Within-group (baseline vs. post-observation) analysis revealed significant difference on VIFT (p < 0.001), PSS (p = 0.008), while no significant differences were found on ASR (p = 0.949) and TSA score (p = 0.619). Significant correlations were found between ΔPSS and match total distance (r = 0.444; p = 0.050), match Z2 (r = 0.481; p = 0.032) and match Z3 (r = 0.454; p = 0.044). Significant correlations were found between ΔTSA and match total distance (r = 0.457; p = 0.043), match Z1 (r = 0.451; p = 0.046), match Z2 (r = 0.500; p = 0.025) and match Z3 (r = 0.468; p = 0.037). Significant improvements were observed after the period of observation. However, the fitness baseline level and the accumulated training load in the small-sided games seem to have no significant impact on the observed improvements.



#7 Bout duration and number of players of soccer small-sided games affect perceived enjoyment, physiological responses, and technical-tactical performance

Reference: Sci Med Footb. 2022 Nov;6(4):503-510. doi: 10.1080/24733938.2021.2009123. Epub 2021 Dec 1.

Authors: Zouhaier Farhani, Raouf Hammami, Javier Gene-Morales, Sabri Gaied Chortane, Anissa Bouassida, Alvaro Juesas, Juan C Colado

Summary: The wim awas to compare perceived enjoyment (PE), % of heart rate peak (%HRpeak), blood lactate (La), rating of perceived exertion (RPE), and technical-tactical performance of soccer players after four-a-side (4vs4) and three-a-side (3vs3) small-sided games (SSGs) with goalkeepers. Sixteen males (20.7 ± 0.7 years; experience: 6.9 ± 1.2 years) completed and were measured after six sessions of SSGs (one twelve-minute bout (1x12), two six-minute bouts (2x6), and three four-minute bouts (3x4), both 3vs3 and 4vs4). Repeated measurements ANOVA evaluated significant differences (p ≤ 0.05). There was higher PE for 1 × 12 compared to 2 × 6 (effect sizes [ES] = 1.53 [3vs3 and 4vs4]) and 3 × 4 (ES = 3.13 [4vs4] and 4.16 [3vs3]). Continuous bout duration (1x12) was characterized by a significantly greater percentage of successful passes compared to 2 × 6 (ES = 2.57 [4vs4] and 1.79 [3vs3]) and 3 × 4 (ES = 2.14 [4vs4] and 1.73 [3vs3]), and minor ball loss rate (2x6: ES = 2.14 [4vs4] and 1.11 [3vs3]; 3x4: ES = 2.11 [4vs4] and 1.57 [3vs3]). The percentage of successful tackles was only significantly greater for 1 × 12 in 4vs4 (ES = 0.83 [2x6] and 0.86 [3x4]) and successful duels in 3vs3 (ES = 1.41 [2x6] and 1.43 [3x4]). Significantly greater %HRpeak for 1 × 12 compared to 2 × 6 (ES = 1.02 [4vs4] and 0.81 [3vs3]) and 3 × 4 (ES = 1.04 [4vs4] and 0.99 [3vs3]) was observed, La differences were only significant in 3vs3 (ES = 1.60 [2x6] and 1.30 [3x4]). Greatest RPE were encountered in 3 × 4 (4vs4) and 1 × 12 and 3 × 4 (3vs3). Significant differences existed between the 3vs3 and 4vs4 designs with a non-clear pattern of better results for neither of both. Therefore, coaches should consider longer continuous bouts when programming SSGs-based training to significantly increase PE, technical-tactical performance, and training load.



#8 Team's Average Acute:Chronic Workload Ratio Correlates with Injury Risk in NCAA Men's Soccer Team

Reference: PM R. 2022 Nov 21. doi: 10.1002/pmrj.12923. Online ahead of print.

Authors: David R Bakal, Tyler R Friedrich, Gerald Keane, Brian White, Eugene Y Roh

Summary: Research in multiple sports has shown that an individual's acute:chronic workload ratio (ACWR) correlates with injury. However, tailoring team trainings to each individual's ACWR is technically challenging, and has not been found to decrease injury risk. We aimed to establish a more feasible method of utilizing the ACWR for injury prevention in soccer. In an NCAA men's soccer team, we assessed whether the team's average ACWR, as opposed to that of each individual, correlated with injuries sustained throughout the season. Injury and workload data were retrospectively evaluated for all players (n=23) of an NCAA men's soccer team during one 18-week season. Workload data for 5 GPS-derived workload variables (total distance, high-speed distance, accelerations, player load, and average velocity) were used to calculate the team's average daily acute and chronic workloads (accumulated load for each variable during the past 3 and 28 days, respectively), and uncoupled ACWRs (acute workload divided by chronic workload for each variable). A retrospective cohort design was used to compare the team's workloads and ACWRs on days where ≥1 injury occurred versus days where 0 injuries occurred using binary logistic regression models. Trainings/games with injuries had higher acute workloads, lower chronic workloads, and higher ACWRs for all 5 workload variables. In multivariable analysis, risk factors for injury included a low chronic workload for total distance (OR 7.23, p=0.024) and an ACWR >1.4 for accelerations (OR 4.34, p=0.029). The team's injury risk was greater with low distance accumulation during the chronic period, and with an elevated ACWR for accelerations. Future intervention-based studies aimed at using ACWR load-management principles as a method of decreasing injury risk in soccer can consider tracking the team's average values with the goal of maintaining a consistent chronic workload for total distance and avoiding elevations in the ACWR for accelerations. This article is protected by copyright. All rights reserved.



#9 Peak Height Velocity Affects Injury Burden in Circa-PHV Soccer Players

Reference: Int J Sports Med. 2022 Nov 21. doi: 10.1055/a-1983-6762. Online ahead of print.

Authors: Xabier Monasterio, Susana M Gil, Iraia Bidaurrazaga-Letona, Jose A Lekue, Gontzal Diaz-Beitia, Juan M Santisteban, Dae-Jin Lee, Lore Zumeta-Olaskoaga, Imanol Martin-Garetxana, Jon Larruskain

Summary: Growth and maturation are potential risk factors for soccer injuries. This research sought to describe how peak height velocity (PHV) affects overall and specific injury burden in circa- and post-PHV elite academy soccer players. Injuries and growth data collected from 2000-2020 were retrospectively studied. Longitudinal height records for 124 players were fitted with the Super-Imposition by Translation and Rotation model to calculate PHV (cm/year) and age at PHV. Players were classified according to PHV percentile (fast: ≥75th; average: 25-75th; slow: ≤25th) and maturity status (circa- or post-PHV). Overall and specific injury burden (days lost/player-season) and rate ratios for comparisons between groups were calculated based on zero-inflated negative binomial models. Confidence intervals were calculated at the 95% confidence level (CI) and the significance level was set at <0.05. In circa-PHV, players with fast PHV had 2.6 (CI: 1.4-4.8)- and 3.3 (CI:1.3-6.7)-times higher overall burden and 2.9 (CI:1.1-7.1)- and 4.1 (CI: 1.4-15.2)-times higher for growth-related injury burden compared to players with average and slow PHV, respectively. Regular monitoring of growth seems important to detect players at higher risk for being disrupted by growth-related injuries.



#10 Ultrasound-Guided Percutaneous Needle Electrolysis Combined With Therapeutic Exercise May Add Benefit in the Management of Soleus Injury in Female Soccer Players: A Pilot Study

Reference: J Sport Rehabil. 2022 Nov 21;1-7. doi: 10.1123/jsr.2022-0021. Online ahead of print.

Authors: Blanca De-la-Cruz-Torres, Beatriz Romero-Rodríguez, Carlos Romero-Morales

Summary: The performance of sprints during male soccer matches usually is slow medium paced, where the soleus and gastrocnemius (ankle plantar flexors) play a very important role. As in male soccer, soleus injuries should be considered in female soccer; but the scientific evidence is very limited in this case. The aim was to determine whether adding an ultrasound-guided percutaneous needle electrolysis (US-guided PNE) technique to a specific exercise program improved perceived pain at stretching and at palpation, ankle dorsiflexion range of motion, muscle fatigue, and sport performance in women soccer players with soleus injury. This pilot study recruited 20 female players with chronic soleus injury (type 1, characterized by hypoechoic image) who were assigned to one of 2 groups: an experimental group (exercise program + US-guided PNE; n = 10) or a control group (exercise program + sham stimulation; n = 10). Pain intensity, dorsiflexion range of motion, knee-flexion heel raise test, curve sprint test, and the global rating of change scale were analyzed at baseline and after treatment (4 wk) and there was no further follow-up. Pain intensity at palpation and at stretching, dorsiflexion range of motion, and heel raise test values showed significant improvements (P < .05) between pretreatment and posttreatment for both groups, however, no significant differences were observed between groups. Curve sprint tests did not show significant differences between pretreatment and posttreatment for either group or between groups. However, the percentage of changes always revealed better values in favor of the PNE group. Both groups showed good player satisfaction with the therapies. The application of the US-guided PNE combined with a specific exercise program may cause clinical benefits in the treatment of female soccer players with soleus injury.



#11 Modelling the relationships between EEG signals, movement kinematics and outcome in soccer kicking

Reference: Cogn Neurodyn. 2022 Dec;16(6):1303-1321. doi: 10.1007/s11571-022-09786-2. Epub 2022 Feb 25.

Authors: Luiz H Palucci Vieira, Christopher Carling, João Pedro da Silva, Felipe B Santinelli, Paula F Polastri, Paulo R P Santiago, Fabio A Barbieri

Summary: The contribution of cortical activity (e.g. EEG recordings) in various brain regions to motor control during goal-directed manipulative tasks using lower limbs remains unexplored. Therefore, the aim of the current study was to determine the magnitude of associations between EEG-derived brain activity and soccer kicking parameters. Twenty-four under-17 players performed an instep kicking task (18 m from the goal) aiming to hit 1 × 1 m targets allocated in the goalpost upper corners in the presence of a goalkeeper. Using a portable 64-channel EEG system, brain oscillations in delta, theta, alpha, beta and gamma frequency bands were determined at the frontal, motor, parietal and occipital regions separately for three phases of the kicks: preparatory, approach and immediately prior to ball contact. Movement kinematic measures included segmental linear and relative velocities, angular joint displacement and velocities. Mean radial error and ball velocity were assumed as outcome indicators. A significant influence of frontal theta power immediately prior to ball contact was observed in the variance of ball velocity (R 2 = 35%, P = 0.01) while the expression of occipital alpha component recorded during the preparatory phase contributed to the mean radial error (R 2 = 20%, P = 0.049). Ankle eversion angle at impact moment likely mediated the association between frontal theta power and subsequent ball velocity (β = 0.151, P = 0.06). The present analysis showed that the brain signalling at cortical level may be determinant in movement control, ball velocity and accuracy when performing kick attempts from the edge of penalty area. Trial registration number #RBR-8prx2m-Brazilian Registry of Clinical Trials ReBec.



#12 Low sleep quality and morningness-eveningness scale score may impair ball placement but not kicking velocity in youth academy soccer players

Reference: Sci Med Footb. 2022 Nov;6(4):528-538. doi: 10.1080/24733938.2021.2014550. Epub 2021 Dec 15.

Authors: Luiz H Palucci Vieira, Michele Lastella, João Pedro da Silva, Tiago Cesário, Felipe B Santinelli, Gabriel F Moretto, Paulo R P Santiago, Fabio A Barbieri

Summary: The current study examined the possible relationships between one-off single night sleep metrics and subsequent kicking performance in a youth soccer context. Twenty-eight under-17 academy players (15.9 ± 0.8 years-old) completed a kick testing protocol consisting in 20 attempts, 18 m from the goal and against a goalkeeper. Four digital video cameras (240 Hz) allowed to determine 3-D approach run, lower limb and ball velocities. Two additional cameras (60 Hz) were used to calculate 2-D mean radial error, bivariate variable error and accuracy. Over 24 h prior to testing, players were monitored by wrist actigraphy to determine their sleep indices. Self-reported sleep quality, sleepiness and chronotype scale scores (Horne and Östberg morningness-eveningness questionnaire) were also collected immediately before kicking experiment. Multiple linear regressions indicated that wake up time and chronotype contributed to 40% of mean radial error. Self-reported sleep quality influenced respectively on 19% and 24% of accuracy and bivariate variable error variances. Taken together self-reported sleep quality and wake up time explained 33% of accuracy (all p < 0.05). Indicators of kicking velocity were non-significantly correlated with sleep (r = -0.30-0.29; p > 0.05). One-off sleep measures showed some sensitivity to acutely detect inter-individual oscillations in kicking performance. Low perceived sleep quality, later wake up time and a chronotype toward evening preference seem either related to immediately subsequent worst ability of ball placement when kicking. Monitoring sleep-wake transition and perceived sleep quality may be important to help prevent acute performance declines in targeting the goal during kick attempts from the edge of penalty area.



#13 The impact of simulated soccer match-play on hip and hamstring strength in academy soccer players

Reference: Sci Med Footb. 2022 Nov;6(4):465-472. doi: 10.1080/24733938.2021.1973080. Epub 2021 Aug 31.

Authors: Jamie Salter, R Cresswell, D Forsdyke

Summary: Together, the burden of hamstring and hip and groin injuries in soccer is substantial and the risk of re-injury in these areas is high. Reduced muscle strength has been identified as an important modifiable intrinsic risk factor of injury. However, little is known regarding the within-match changes in hip and hamstring muscle strength in order to inform early detection and management strategies. Seventy-one male soccer players (age, 19.2 ± 0.9 yrs; height, 175.9 ± 5.8 cm; weight, 73 ±8.2 kg) from an international academy completed a fixed soccer-specific activity profile (SAFT90). Isometric hip and eccentric hamstring strength were measured after a standardised 5-min warm-up and repeated at half time and full time. Repeated-measures ANOVA were used to determine changes in muscle strength with magnitude-based decisions used to express probabilistic uncertainty. Findings indicate that i) there was likely to very likely substantial changes in isometric hip strength (-9.9-15.7%) and ii) no substantial changes in eccentric hamstring strength (-2.6-5.1%). By extrapolating these findings, it can be inferred that reduced isometric hip strength during match play may be one risk factor for injury, especially during periods of fixture congestion and practitioners should routinely assess muscle strength to inform training and match exposure based on player readiness. In doing so, it is likely that practitioners may enhance player availability and minimise injury incidence.



#14 Classification and determinants of passing difficulty in soccer: a multivariate approach

Reference: Sci Med Footb. 2022 Nov;6(4):483-493. doi: 10.1080/24733938.2021.1986227. Epub 2021 Oct 15.

Authors: Murilo Merlin, Allan Pinto, Alexandre Gomes de Almeida, Felipe A Moura, Ricardo Da Silva Torres, Sergio Augusto Cunha

Summary: Usually, the players' or teams' efficiency to perform passes is measured in terms of accuracy. The degree of difficulty of this action has been overlooked in the literature. The present study aimed to classify the degree of passing difficulty in soccer matches and to identify and to discuss the variables that most explain the passing difficulty using spatiotemporal data. The data used corresponds to 2,856 passes and 32 independent variables. The Fisher Discriminant Analysis presented 72.0% of the original grouped cases classified correctly. The passes analyzed were classified as low (56.5%), medium (22.6%), and high difficulty (20.9%), and we identified 16 variables that best explain the degree of passing difficulty related to the passing receiver, ball trajectory, pitch position and passing player. The merit and ability of the player to perform passes with high difficulty should be valued and can be used to rank the best players and teams.In addition, the highlighted variables should be looked carefully by coaches when analyzing profiles, strengths and weaknesses of players and teams, and talent identification context. The values found for each variable can be used as a reference for planning training, such as small side games, and in future research.



#15 The influence of short sprint performance, acceleration, and deceleration mechanical properties on change of direction ability in soccer players-A cross-sectional study

Reference: Front Physiol. 2022 Nov 2;13:1027811. doi: 10.3389/fphys.2022.1027811. eCollection 2022.

Authors: Qingshan Zhang, Alexandre Dellal, Karim Chamari, Pierre-Hugues Igonin, Cyril Martin, Christophe Hautier

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Summary: The study investigated the relationship between short sprint performance and mechanical parameters obtained during the acceleration and deceleration tasks with the change of direction (COD) performance in female and male soccer players. The acceleration and deceleration ability were compared in the "High/Fast" versus "Low/Slow" COD performance group based on a median split analysis in each sex group. One hundred three French soccer players were assessed for the sprinting Force-Velocity (F-V) profile (i.e., theoretical maximal force [F0], velocity [V0], power [Pmax]), 10 m performance, linear deceleration test (maximal braking force [HBFmax], braking power [BPmax], deceleration [Decmax]), and COD performance using 505-test. The 10 m performance was strongly associated with 505-test performance (ES = [0.64 to 0.71]), whereas the sprinting F-V profiles parameters were weakly to moderately correlated with 505- performance (ES = [-0.47 to -0.38]). The BPmax was also moderately associated with 505-test performance (ES: range = [-0.55 to -0.46]). In addition, the High/Fast female COD group presented higher F0, Pmax, HBFmax, and BPmax than the Low/Slow group, whereas the male groups presented very few mechanical differences. Multiple regression analysis shows that the COD performance of male players was determined by 10 m performance and maximum deceleration power. In contrast, no statistically significant model could be found to determine the change of direction performance in female players. In conclusion, the current finding indicated that the only variable strongly associated with COD performance was the linear 10 m sprint time. In the same way, the mechanical parameters obtained from acceleration and deceleration seemed to play a non-neglectable role in this population.



#16 The reality of organizational health in the Central Iraqi Football Federation from the point of view of those who manage the implementation of the annual curriculum

Reference: J Popul Ther Clin Pharmacol. 2022 Nov 19;29(4):e55-e68. doi: 10.47750/jptcp.2022.947. eCollection 2022.

Authors: Saba Qays Ghadhban

Summary: The aim of this research is to identify the strengths and weaknesses of organizational health in the Iraqi Central Handball Federation from the point of view of those who manage the implementation of the annual curriculum, and adopt a descriptive approach in the method of studying the case. This is based on a sample of administrators of the Iraqi Handball Federation curriculum [trainers, governors, members, president, the 138 members of the Central Federation's Administrative Authority, the President, members of the sub-federations of the sports market (2021/2022) selected deliberately by 100% and then divided into statistical analysis sample (30), reconnaissance sample (10), and application sample (98)]. The regulatory health questionnaire in its Italian version was prepared to suit the specificity of the research and the type of sample it was assigned in accordance with systematic sequential steps for its acceptance of the main measurement cad actor in this research. This was then applied to address the problem researched, and its data were processed by the system (SPSS) to make conclusions and applications that help regulatory health in support of the efforts of the Central Handball Federation to implement the annual curriculum from the point of view of those who manage its implementation, and help activate the role of sponsors to manage the implementation of the annual curriculum in the Central Handball Federation effectively, and was then applied to address the research problem. It has complementary factors that need to be available at a high level in the Central Handball Federation to help manage the implementation of the annual curriculum in full, and its specificity in managing the implementation of the annual curriculum in the Central Handball Federation requires comprehensiveness and the need for its elements to achieve a high level of it. It is necessary to support them in the formation of the Central Handball Federation to further activate the role of the worlds and determine their role and avoid feeling the loss of efforts, a careful and periodic review of the level of organizational health must be conducted before planning the annual curriculum in the Central Handball Federation, modifying the paths of weakness, supporting its strengths and taking into account its suitability in order to achieve the goals when implemented later.



#17 Monitoring the beautiful adapted game: a 3-year prospective surveillance study of injuries in elite English Para football

Reference: Sci Med Footb. 2022 Nov;6(4):415-420. doi: 10.1080/24733938.2021.1984556. Epub 2021 Oct 1.

Authors: Richard Weiler, Evert Verhagen, Aileen Taylor, Osman Hassan Ahmed

Summary: Para football is currently played in impairment-specific formats by thousands of people worldwide. To date, there have been no prospective longitudinal injury surveillance studies. This study aimed to implement a prospective injury surveillance study within elite English Para football and analyse the injury risk within the England Blind and Cerebral Palsy (CP) squads. Match and training injury data based on a 'time loss' definition were collected and analysed for each squad including incidence per 1,000 player hours, severity, injury location and associated event of injury. Injury incidence were lower in training than matches (CP 67.6/1000 player match hours (CI 33.8-135.2) and 5.7/1000 training hours (CI 3.8-8.7) and Blind 44.0/1000 player match hours (CI 26.1-74.3) and 5.5/1000 training hours (CI 3.5-8.6). Training injuries were more severe than match injuries across both squads (CP median 12 days lost in matches and 16 training and Blind median days 5 matches and 12 training). 73% Blind and 74% CP footballer injuries were to the lower limb and 17% head and neck equally across both Para football squads. 'Muscle and tendon injuries' (51%) represented the greatest proportion of injuries for CP footballers, and 'joint (non-bone)/ligament injuries' (43%) for Blind footballers. Collaboration and implementation of higher quality surveillance methodology and data collection in Para sport with greater athlete numbers are needed to inform injury prevention strategies.



#18 Perceiving, reporting and managing an injury - perspectives from national team football players, coaches, and health professionals

Reference: Sci Med Footb. 2022 Nov;6(4):421-433. doi: 10.1080/24733938.2021.1985164. Epub 2021 Oct 21.

Authors: Sandro Vella, Caroline Bolling, Evert Verhagen, Isabel Sarah Moore

Summary: Injury perceptions and related risk-mitigating interventions are context-dependent. Despite this, most injury surveillance systems are not context-specific as they do not integrate end-users perspectives. The purpose was to explore how Maltese national team football players, coaches, and health professionals perceive a football-related injury and how their context influences their perceptions and behaviours towards reporting and managing a football injury. 13 semi-structured interviews with Maltese female and male national team football players (n = 7), coaches (n = 3), and health professionals (n = 3) were conducted. Data were analysed using thematic analysis. Three themes were identified: (1) How do I perceive an injury? Consisted of various constructs of a sports injury, yet commonly defined based on performance limitations. (2) How do I deal with an injury? Encapsulated the process of managing the injury (3) What influences my perception, reporting and management of an injury? Comprised personal and contextual factors that influenced the perception and, consequently, the management of an injury. Performance limitations should be used as part of future injury definitions in injury surveillance systems. Human interaction should be involved in all the processes of an injury surveillance framework, emphasising its active role to guide the injury management process.



#19 Quantity and quality of sleep in young players of a professional football club

Reference: Sci Med Footb. 2022 Nov;6(4):539-544. doi: 10.1080/24733938.2021.1962541. Epub 2021 Aug 17.

Authors: Ana Merayo, Jose Miguel Gallego, Oscar Sans, Lluis Capdevila, Alex Iranzo, Dai Sugimoto, Gil Rodas

Summary: The aim was to investigate the quantity and quality of sleep hours in young athletes in a professional football club, to study if there is a significant relationship with mood state and subjective well-being, and to identify the relationship between sleep and quarterly academic performance. We also explored the relationship between sleep and quarterly academic performance. The study included 261 players of the various age group categories from football at Barcelona Football Club (average age:13.04 ± 3.16). Participants maintained a sleep diary and completed questionnaires on their mood state and the quantity and quality of their sleep. 70% of the athletes slept less hours than recommended by the American National Sleep Foundation. Athletes with worse quantity and quality of sleep showed negative effects on academic results. The results show that the majority of young players sleep less than recommended and show that those who sleep more hours obtain better academic results.



#20 Injuries are negatively associated with player progression in an elite football academy

Reference: Sci Med Footb. 2022 Nov;6(4):405-414. doi: 10.1080/24733938.2021.1943756. Epub 2021 Aug 17.

Authors: Jon Larruskain, Jose A Lekue, Imanol Martin-Garetxana, Irantzu Barrio, Alan McCall, Susana M Gil

Summary: The aim was to investigate the association of injuries with male football player continuity, progression and chances of reaching the First team in an elite academy. Injuries and exposure time were prospectively recorded, following the FIFA guidelines, over 6 seasons (2011-2017) in Under (U)12, U14, U16, U19, 2nd/3rd team and First team players from the same professional football club. U19 and 2nd/3rd team players progressing to the next level had a lower injury burden and higher match availability compared to players that did not progress. Injury burden was lower in players progressing from U12 to U14. All players progressing from the 2nd/3rd teams to the First team had a match availability higher than 84% and did not suffer an anterior cruciate ligament (ACL) rupture or an injury requiring over 200 (+200) days to return to play. In U19 and 2nd/3rd team players, injuries requiring +100 and +200 days to return to play, ACL ruptures and groin pain, but not hamstring and ankle ligament injuries, were associated with lower odds of continuing in the academy each season. Injuries were negatively associated with player progression, and injury prevention and return-to-play strategies should be a priority for football academies.



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