Those players younger than 14 years incurred more injuries in training and sustained more growth-related overuse disorders. Older players were more often injured during matches. Injury incidence and the frequency of overuse disorders were highest early in the season.

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The survey revealed the most common perceptions and practices of premier league football clubs internationally regarding risk factors, testing and preventative exercises. The findings can enable reduction of the gap between research and practice.

The results, when compared with those of other investigations on female soccer players, revealed high rates of both traumatic injury and match injury, whereas recurrence of injury was low. Injuries, notably sprains, to the ankle were common, suggesting a need for the implementation of specific injury prevention strategies for this joint.

PurposeTo systematically review the scientific level of evidence for the ‘Top 3’ risk factors, screening tests and preventative exercises identified by a previously published survey of 44 premier league football (soccer) teams. Also, to provide an overall scientific level of evidence and graded recommendation based on the current research literature.MethodsA systematic literature search (Pubmed [MEDLINE], SportDiscus, PEDRO and Cochrane databases). The quality of the articles was assessed and a level of evidence (1++ to 4) was assigned. Level 1++ corresponded to the highest level of evidence available and 4, the lowest. A graded recommendation (A: strong, B: moderate, C: weak, D: insufficient evidence to assign a specific recommendation) for use in the practical setting was given.ResultsFourteen studies were analysed. The overall level of evidence for the risk factors previous injury, fatigue and muscle imbalance were 2++, 4 and ‘inconclusive’, respectively. The graded recommendation for functional movement screen, psychological questionnaire and isokinetic muscle testing were all ‘D’. Hamstring eccentric had a weak graded ‘C’ recommendation, and eccentric exercise for other body parts was ‘D’. Balance/proprioception exercise to reduce ankle and knee sprain injury was assigned a graded recommendation ‘D’.ConclusionsThe majority of perceptions and practices of premier league teams have a low level of evidence and low graded recommendation. This does not imply that these perceptions and practices are not important or not valid, as it may simply be that they are yet to be sufficiently validated or refuted by research.

The purpose of the present study was to investigate injury according to biological maturity in elite under-14 youth football players based at the National Football Institute, France. Over 10 seasons, injury incidence, severity and distribution were compared in 233 players classed according to individual biological maturity determined by skeletal age into three cohorts as early, normal and late maturers.A non-significant higher injury incidence was found in early and normal maturers compared with late maturers. In contrast, the latter group sustained a significantly higher incidence of major injuries compared with early maturers (0.3 vs 0.6 vs 0.9, P=0.039). A significantly higher incidence of osteochrondoses was reported in normal and late maturers (0.3 vs 0.7 vs 0.9, P=0.014), whereas tendinopathy incidence was greater in early and normal maturers (0.06 vs 0.08 vs 0.02, P=0.033). Early maturers incurred the highest incidence of groin strains and re-injuries (P<0.05). There was no significant difference between groups in the seasonal disposition of injury.Biological maturity status did not significantly affect overall injury incidence in elite French youth football players, although there were differences between maturity groups when patterns of injury location, type, severity and re-injury were analyzed.

The aims of this study were twofold: (1) to characterize repeated high-intensity movement activity profiles of a professional soccer team in official match-play; and (2) to inform and verify the construct validity of tests commonly used to determine repeated-sprint ability in soccer by investigating the relationship between the results from a test of repeated-sprint ability and repeated high-intensity performance in competition. High-intensity running performance (movement at velocities 419.8 km Á h 71 for a minimum of 1 s duration) was measured in 20 players using computerized time-motion analysis. Performance in 80 French League 1 matches was analysed. In addition, 12 of the 20 players performed a repeated-sprint test on a non-motorized treadmill consisting of six consecutive 6 s sprints separated by 20 s passive recovery intervals. In all players, most consecutive high-intensity actions in competition were performed after recovery durations !61 s, recovery activity separating these efforts was generally active in nature with the major part of this spent walking, and players performed 1.1 + 1.1 repeated high-intensity bouts (a minimum of three consecutive high-intensity bouts with a mean recovery time 20 s separating efforts) per game. Players reporting lowest performance decrements in the repeated-sprint ability test performed more high-intensity actions interspersed by short recovery times ( 20 s, P 5 0.01 and 30 s, P 5 0.05) compared with those with higher decrements. Across positional roles, central-midfielders performed more high-intensity actions separated by short recovery times ( 20 s) and spent a larger proportion of time running at higher intensities during recovery periods, while fullbacks performed the most repeated high-intensity bouts (statistical differences across positional roles from P 5 0.05 to P 5 0.001). These findings have implications for repeated high-intensity testing and physical conditioning regimens.

In this study, the effects of a prolonged period of fixture congestion (8 successive official matches in 26-days) on physical performance and injury risk and severity in a professional soccer team were investigated. Computerised motion-analysis was used to analyse the overall distance covered and that run at light-(0.0-11.0 km•h -1 ); low-(11.1-14.0 km•h -1 ); moderate-(14.1-19.7 km•h -1 ) and high-intensities (≥19.8 km•h -1 ) for the team as a whole. Distances were measured in metres per minute. Information on match injuries was recorded prospectively. The overall distance covered varied across successive matches (p<0.001) as more distance was run in games 4 and 7 compared to 2 and 3 respectively ( When comparing match halves, there were no differences across games in overall or high-intensity distance covered and performance in these measures was similar for matches played before, during and after this period. Globally, no difference over the 8 games combined was observed between the reference team and opponents in any of the performance measures whereas the overall distance covered and that in low-(both p<0.001) and high-intensity running (p=0.040) differed in individual games. The incidence of match injury during the congested fixture period was similar to rates reported outside this period but the mean layoff duration of injuries was substantially shorter during the former (p<0.05). In summary, while the overall distance run and that covered at lower intensities varied across games, high-intensity running performance and injury risk were generally unaffected during a prolonged period of fixture congestion. These results might be linked to squad rotation and post-match recovery strategies in place at the present club.