FSI Football Science Update

Non-contact Anterior Cruciate Ligament Injury Epidemiology in Team-Ball Sports: A Systematic Review with Meta-analysis by Sex, Age, Sport, Participation Level, and Exposure Type.

Chia L, De Oliveira Silva D, Whalan M, McKay MJ, Sullivan J, Fuller CW, Pappas E.

Sports Med. 2022 May 27. doi: 10.1007/s40279-022-01697-w.

This systematic review of 45 studies covering 13 team ball-sports found that the overall proportion of non-contact to total ACL injuries was 55% (females: 63%; males: 50%). The overall incidence of non-contact ACL injuries was 0.07 per 1000 player-hours. Injury incidence was significantly higher in female athletes (0.14 per 1000 player-hours) than male athletes (0.05 per 1000 player-hours). And injury incidence during competition was significantly higher (0.48 per 1000 player-hours) than during training (0.04 per 1000 player-hours).




Effects of Repeated Sprint Training With Progressive Elastic Resistance on Sprint Performance and Anterior-Posterior Force Production in Elite Young Soccer Players.

Le Scouarnec J, Samozino P, Andrieu B, Thubin T, Morin JB, Favier FB.

J Strength Cond Res. 2022 Jun 1;36(6):1675-1681. doi: 10.1519/JSC.0000000000004242.

This study compared 7 elite U19 soccer players that underwent 10 sessions of elastic-resisted repeated sprints on 8 weeks, with 8 U17 players from the same academy (control group) that followed the same protocol without elastic bands. The elastic-resisted training resulted in a significant improvement of the sprint time (-2.1 ± 1.3%) and maximal velocity (Vmax; +3.9 ± 2%) reached during a 30-m sprint. These enhancements were concurrent with an increase in the maximal power output related to AP force (Pmax; +4.9 ± 5.1%%). These results show that sprint capacity of elite young soccer players can be further improved by adding incremental resistance against runner displacement to raise the ability to produce AP force, rather at high velocity in the final phase of the acceleration.




The effect of planning time on penultimate and ultimate step kinematics and subsequent knee moments during sidestepping.

Byrne S, Lay B, Staynor J, Alderson J, Donnelly CJ.

Scand J Med Sci Sports. 2022 May 25. doi: 10.1111/sms.14194.

This study in 60 male amateur Australian Rules football players found that in comparison with unplanned sidestepping, in planned sidestepping at the penultimate step final foot contact, the support foot was placed across the midline of the centre of mass, in the frontal plane, contralateral to the sidestep direction, with greater trunk lateral flexion towards the sidestep direction and greater negative pelvic lateral tilt. As there are clear differences in these preparatory kinematics, planning time should be considered when training and assessing sidestepping manoeuvers and planned and unplanned manoeuvers not be treated as interchangeable skills.




A retrospective analysis of all-cause and cause-specific mortality rates in French male professional footballers.

Orhant E, Carling C, Chapellier JF, Marchand JL, Pradat PF, Elbaz A, Maniez S, Moisan F, Rochcongar P.

Scand J Med Sci Sports. 2022 May 25. doi: 10.1111/sms.14195.

This study in 6114 individuals born in Metropolitan France or in one of its overseas territories who played at least one competitive match in France’s professional football championships between 01/01/1968 and 31/12/2015, found that all-cause, nervous and cardiovascular systems mortality was lower than that for the national population, but that an excess of deaths from dementia was observed in the players (Ratio between observed and expected deaths or Standardized Mortality Ratios (SMR): 3.38) so more than 3 times higher than expected. Career length was not associated with all-cause or cause-specific mortality. Prospective matched-cohort studies are necessary to identify the neurologic impact of participation in professional football.



Return to Play Prediction Accuracy of the MLG-R Classification System for Hamstring Injuries in Football Players: A Machine Learning Approach.

Valle X, Mechó S, Alentorn-Geli E, Järvinen TAH, Lempainen L, Pruna R, Monllau JC, Rodas G, Isern-Kebschull J, Ghrairi M, Yanguas X, Balius R, la Torre AM.

Sports Med. 2022 May 24. doi: 10.1007/s40279-022-01672-5.

This study in 76 hamstrings injuries with complete clinic information and magnetic resonance images sustained by 42 male professional football players from FC Barcelona between February 2010 and February 2020 found that 65.8% were grade 3r in the MLG-R classification, 71.1% affected the biceps femoris long head, and 43.4% were located at the proximal myotendinous junction. Injuries affecting the proximal myotendinous junction had a mean return to play of 31.7 days while those affecting the distal part of the myotendinous junction had a mean return to play of 23.9 days. Grade 3r biceps femoris long head injuries located at the free tendon showed a median return to play time of 56 days while the injuries located at the central tendon had a shorter return to play of 24 days. The MLG-R classification system showed an excellent predictive power with a mean absolute error of 9.8 days. The most important factors to determine the return to play were if the injury was at the free tendon of the biceps femoris long head or if it was a grade 3r injury.