Professional football carries a high risk of injury, especially during matches. The injury rate is 7 times higher compared to training.¹ In this context, having all the players healthy and ready to compete is one of the main preparation goals in top-level football. The monthly financial cost of an injury to a player from a team that participates in the Champions League is 500,000€.² In addition, we must mention the negative consequences on the teams’ performance.  For the team to lose a key game, it can cause extreme sporting and financial problems to a club. The quick return to the field of an injured player is one of the coach’s primary concerns and that of the coaching / medical staff. However, it is well known that a previous injury is one of the most critical risk factors for suffering a relapse in the same area.^3,4

A recent research⁵ has analyzed how the number of training sessions carried out from the moment the player is available to play (return to play) until he plays the match, influences the probability of suffering an injury. The study, published in the British Journal of Sports Medicine in 2020, was based on the analysis of 64 elite teams for 16 consecutive seasons (2001/2002 to 2016/2017). A member of the coaching staff of each club registered injuries and participation in training sessions and matches for each player. The sample included 4,088 players, 16,087 injuries, 4,805 first games after returning from injury, 1,571,448 training sessions, and 303,637 games. The definition of injury is any discomfort suffered by a player due to playing a match or training session, which causes the athlete to be unavailable to participate in the next training session or match. Only moderate and severe injuries (those that forced players to lose 8 days or more) were included in the study.

The results suggest some very relevant conclusions for practice: (i) the frequency of injuries in the first game after an injury was almost double compared to the average that occurred during the season: 46.9 vs. 25.0 injuries / 1,000 game hours. (ii) This high injury rate is mainly due to a 158% increase in muscle injuries. In the first game after an injury, the muscle injury rate was 24.6 injuries / 1,000 game hours, while the average during the season was 9.5 injuries / 1,000 game hours. (iii) However, there are no significant differences in the rate of non-muscular injuries. (iv) Each additional training session that players complete before playing the first match after injury reduced the probability of injury by 7%. This value reaches 13% for muscular injuries, while no significant association was found between the number of sessions completed and the occurrence of a non-muscular injury. In any case, we should take the results with caution. There is no control yet, of content, training load, level of physical condition, or the number of sessions that the players have done before playing the first match after the injury.

The practical applications of this work suggest several aspects to consider for reducing the risk of suffering a new injury when returning to the competition: (i) Controlling loads is a crucial aspect. It is about proposing a gradual return to play until the players adapt to a level like that required in the competition, avoiding very aggressive load peaks. (ii) We must verify that the players are capable enough of using their abilities in the game safely and efficiently. We should ensure a minimum period to work on motor skills and movement skills in the first days after resuming activity as a strategy to reduce the likelihood of injury. (iii) The main task of the medical services is to objectively inform athletes and coaches about their health condition and the risk of injury or poor performance. The athletes and coaches are the ones who must finally evaluate the information and make the decision about returning to the competition. The success of a good decision depends mainly on the good internal communication within the clubs’ staff.⁶

References

¹ Ekstrand J, Hägglund M, Kristenson K, et al. Fewer ligament injuries but no preventive effect on muscle injuries and severe injuries: an 11-year follow-up of the UEFA Champions League injury study. Br J Sports Med 2013;47:732–7.

² Ekstrand, J. Keeping your top players on the pitch: the key to football medicine at a professional level. Br J Sports Med 2013; 47:723–724.

³ Hägglund M, Waldén M, Ekstrand J. Risk factors for lower extremity muscle injury in professional soccer: the UEFA Injury Study. Am J Sports Med 2013;41:327–35.

⁴  Hägglund M, Waldén M, Ekstrand J. Previous injury as a risk factor for injury in elite football: a prospective study over two consecutive seasons. Br J Sports Med 2006;40:767–72

⁵ Bengtsson H, Ekstrand J, Waldén M, et al. Br J Sports Med Epub ahead of print. doi:10.1136/ bjsports-2019-100655.

⁶Ekstrand J, Lundqvist D, Davison M, D’Hooghe, M, Pensgaard, A. Communication quality between the medical team and the head coach/manager is associated with injury burden and player availability in elite football clubs Br J Sports Med 2019; 53: 304-308