FSI Football Science Update

Evaluation of the Playing Time Benefits of Foreign Players in the Big-5 European Football Leagues.

Zhang H(1), Jiang J(1).

J Hum Kinet. 2022 Nov 8;84:238-249. doi: 10.2478/hukin-2022-000072. eCollection 2022 Oct

This study constructed a benefit model based on playing time and game points to evaluate the contribution of foreign players to their clubs in the Big-5 European leagues (2013/2014-2017/2018 seasons). Foreign players in the Bundesliga had the highest playing time benefits (PTBs) followed by La Liga, the Premier League, Serie A and Ligue 1. Foreign players from South America had the highest PTBs in the Big-5 leagues, while those from Africa had the lowest PTBs. PTBs of foreign players in the forward position were lower than those of foreign players in the defender position. The country that produced foreign players in the Big-5 leagues with the highest total PTBs was Brazil, followed by Argentina, Spain and France.


Incidence and prevalence of hamstring injuries in field-based team sports: a systematic review and meta-analysis of 5952 injuries from over 7 million exposure hours.

Maniar N(1)(2), Carmichael DS(3), Hickey JT(3)(2), Timmins RG(3)(2), San Jose AJ(3), Dickson J(4), Opar D(3)(2).

Br J Sports Med. 2022 Dec 1:bjsports-2021-104936. doi: 10.1136/bjsports-2021-104936. Online ahead of print.

This systematic review and meta-analyse of 63 articles encompassing 5952 injuries and 7 262 168 hours of exposure across six field-based team sports (soccer, rugby union, field hockey, Gaelic football, hurling and Australian football) found that hamstring injury incidence was 0.81 per 1000 hours, representing 10% of all injuries, with 13% of the athletes experiencing a hamstring injury over a 9-month period. Hamstring injury incidence increased 6.4% for every 1 year of increased age, was 9.4-fold higher in matches compared with training scenarios and was 1.5-fold higher on grass compared with artificial turf surfaces. Hamstring injury incidence was not significantly different between these sports and has not significantly changed over the last 30 years.


Neuromuscular characteristics of agonists and antagonists during maximal eccentric knee flexion in soccer players with a history of hamstring muscle injuries.

Ritzmann R(1), Strütt S(2)(3), Torreno I(3), Riesterer J(2), Centner C(2), Suarez-Arrones L(4)(5).

PLoS One. 2022 Dec 1;17(12):e0277949. doi: 10.1371/journal.pone.0277949. eCollection 2022

This study compared 20 elite soccer players with a previous unilateral muscle injury in the M. biceps femoris (BF) long head with 20 without this antecedent. Reduced maximal eccentric flexion torque and rate of torque development were found, correlatedly with diminished agonistic myoelectrical activity in the BF. Simultaneously, antagonistic myoelectric activity was increased, showing persistent dysfunctional synergist and antagonist neural hamstrings function after injury.


Effects of Fatigue Induced by Repeated Sprints on Sprint Biomechanics in Football Players: Should We Look at the Group or the Individual?

Romero V(1), Lahti J(2), Castaño Zambudio A(1), Mendiguchia J(3), Jiménez Reyes P(1), Morin JB(4).

Int J Environ Res Public Health. 2022 Nov 8;19(22):14643. doi: 10.3390/ijerph192214643

This study on 51 football players performing 12 maximal 30m sprints with 20 s recovery between each sprint found a large decrease in maximal power output and less efficiency in horizontally orienting the ground reaction force. However, fatigue affected the kinematics in a different way for each player, and these individual changes were associated with either higher or lower hamstring length and thus strain.