A Systematic Review of Effects on ACL Injury of Soccer Shoe Outsoles, Soccer Playing Field Surfaces, and Outsole–Surface Interface: Comparison
Please note this is a comparison between Version 2 by Camila Xu and Version 1 by Antonio Cicchella.

Soccer is a sport with a high incidence of injuries. The most common injury occurs when the anterior cruciate ligament of the knee has undergone a sprain, strain, or partial or total rupture. Besides fitness factors (e.g., proprioception, balance and strength capabilities), a principal cause of ACL injuries is sport shoes and playing surfaces. Especially with the emergence of artificial surfaces (rubbers, turfs, concrete, asphalt, red turf), the ACL injuries dramatically increase. The cost of ACL injuries is high both in terms of career termination and in social and economic costs. Thus, it is necessary to understand the impact of sport shoes and playing surfaces on the ACL and how it can be mitigated. The present literature review followed the PRISMA methodology to identify the major biomechanical factors influencing the behavior of surfaces and shoes in relation to the ACL damage. Fifty-eight papers were identified. After reviewing the mechanism of injuries, we identified several distinct factors: type of outsole and mechanical arrangement of the outsoles; shear forces; characteristics of artificial turf surfaces; effect of weather on artificial surface aging and change in mechanical characteristics; outsole/ground interface; and the frictional, tractional and rotational forces in the pathogenesis of ACL injuries in soccer.

  • soccer
  • ACL
  • injuries
  • shoes
  • surfaces
  • biomechanics

As one of the most popular sports in the world, soccer has an enormous number of participants and quite a high injury risk. Hammer et al. [1], in a cohort study of contact and noncontact injuries in sports among high school students during the 2002–2009 and 2012–2013 school years, found that the injury risk for soccer (RR—relative risk, 4.03; 95% CI—confidence interval, 3.70–4.39) was higher than the mean risk of practice overall (RR, 4.01; 95% CI, 3.90–4.12), behind only American football (RR, 5.74; 95% CI, 5.55–5.93) and field hockey (RR, 3.48; 95% CI, 3.10–3.92); its risk of serious injury (RR, 5.97; 95% CI, 4.82–7.39) was also high, just behind ice hockey (RR, 16.0; 95% CI, 9.51–26.9) and American football (RR, 6.48; 95% CI, 6.02–6.98). Marar et al. [2] also concluded that most concussions resulted from participation in American football (47.1%, n = 912), followed by girls’ soccer (8.2%, n = 159). Based on this, it is important to study soccer injuries in terms of both commercial and societal benefits. Our study reviews the relevant literature, which met the inclusion criteria, about the etiology of ACL injuries in soccer in relation to sport shoes and playing surfaces. In professionals, knee injuries represent 13% of all injuries observed as well as 26% of all severe injuries, and of those, 34% were ligament injuries [3]. An ACL injury is highly disabling for soccer players, causing a mean of 183 days of absence in professional (UEFA) players [4]. The mean ligament injury rate for all UEFA teams in the 2020 season was 1.1 injuries for every 1000 h. The mechanics of ACL and knee injuries have been extensively studied. It was measured that 88% of knee injuries in soccer happen as a result of indirect contact with the opponent, but under the pressure of a match-playing situation [5]. Knee valgus loading is the dominant injury mechanism. Sagittal plane biomechanical factors, such as small knee flexion angle, great posterior ground reaction force and great quadriceps muscle force, are the major ACL loading mechanisms [6]. The primary determining factors of injury are intrinsic (bone and muscular biomechanics under load) and extrinsic. Extrinsic non-contact ACL injury risk factors include dry weather and surfaces, and artificial surfaces instead of natural grass [7]. The aim of this review is to provide the state of the art on the influence of sport shoes and playing surface on the mechanics of ACL injuries in soccer.


  1. Hammer, E.; Brooks, M.A.; Hetzel, S.; Arakkal, A.; Comstock, R.D. Epidemiology of Injuries Sustained in Boys’ High School Contact and Collision Sports, 2008-2009 Through 2012–2013. Orthop. J. Sports Med. 2020, 8, 2325967120903699.
  2. Marar, M.; McIlvain, N.M.; Fields, S.K.; Comstock, R.D. Epidemiology of Concussions Among United States High School Athletes in 20 Sports. Am. J. Sports Med. 2012, 40, 747–755.
  3. Our Research. UEFA Elite Club Injury Study 2019/20 Season Report Team X. UEFA. 2024. Available online: https://editorial.uefa.com/resources/0265-115cf1249d3a-c523ddeccfef-1000/uefa_elite_club_injury_study_season_report_2019-20_-_team_x_2_20210118151053.pdf (accessed on 17 May 2024).
  4. Ekstrand, J.; Krutsch, W.; Spreco, A.; van Zoest, W.; Roberts, C.; Meyer, T.; Bengtsson, H. Time before return to play for the most common injuries in professional football: A 16-year follow-up of the UEFA Elite Club Injury Study. Br. J. Sports Med. 2020, 54, 421–426.
  5. Della Villa, F.; Buckthorpe, M.; Grassi, A.; Nabiuzzi, A.; Tosarelli, F.; Zaffagnini, S.; Della Villa, S. Systematic video analysis of ACL injuries in professional male football (soccer): Injury mechanisms, situational patterns and biomechanics study on 134 consecutive cases. Br. J. Sports Med. 2020, 54, 1423–1432.
  6. Yu, B.; Garrett, W.E. Mechanisms of non-contact ACL injuries. Br. J. Sports Med. 2007, 41 (Suppl 1), i47–i51.
  7. Alentorn-Geli, E.; Myer, G.D.; Silvers, H.J.; Samitier, G.; Romero, D.; Lázaro-Haro, C.; Cugat, R. Prevention of non-contact anterior cruciate ligament injuries in soccer players. Part 1: Mechanisms of injury and underlying risk factors. Knee Surg. Sports Traumatol. Arthrosc. 2009, 17, 705–729.
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