Injuries in Swiss non-professional soccer : characteristics, causes, costs, and prevention

Background and aims Soccer is a very popular sport in Switzerland. In addition to an increasing number of formal players who play soccer in clubs, many also undertake this sport in non-organised, informal contexts. However, playing soccer is associated with a high risk of injury. In Switzerland, both the number of soccer-related injuries and the corresponding costs have increased considerably in recent years. Consequently, soccer injuries represent a substantial financial and psychosocial burden for society. In recent years, various preventive measures have been taken to reduce injuries related to soccer in Switzerland. In order to be able to develop effective prevention strategies, knowledge about injury characteristics, causes, mechanisms and risk factors is essential. Nevertheless, there are fewer studies focussing on injuries in non-professional soccer than in professional soccer. In particular, detailed information is scarce about soccer-related injuries amongst specific groups of players, injury causes and mechanisms, and injury costs. Likewise, little is known about the implementation of preventive measures in the real-world context of amateur soccer. This is primarily due to the fact that such investigations are very time-consuming and difficult to carry out. Thus, the overall aim of this PhD thesis is to expand the knowledge about injuries in Swiss non-professional soccer, in particular by focussing on injury setting, characteristics, causes, and costs. Another fundamental aim of this thesis is to analyse changes in the incidence of injury in Swiss amateur soccer and to examine the implementation of preventive measures in a real-world context. Methods Two fully structured, retrospective telephone surveys were conducted. In the first survey, the Suva study, a random sample of 708 persons who were injured while playing soccer between July 2013 and June 2014 and who reported this accident to the Swiss National Accident Insurance Fund (Suva) were interviewed in detail about the injury context, injury characteristics and injury causes. One year after the accident, the responses from the interviews were linked to the corresponding injury costs provided by Suva. In the second survey, the coaches study carried out in 2015, a representative sample of 1008 Swiss amateur soccer coaches were interviewed about the frequency of injuries in their teams and the implementation of preventive measures and injury prevention programmes. 1076 injuries which occurred during 3964 amateur soccer games and 525 injuries which occurred during 8338 training sessions were analysed. The information collected was compared with two previous surveys of Swiss amateur soccer coaches conducted in 2008 (n = 1015) and 2004 (n = 1029). Results Analysis showed that 30% of injuries in non-professional soccer requiring medical attention happened during informal soccer play, 21% during formal training and 49% during formal soccer games. Furthermore, there were key differences between these non-professional soccer settings with regard to injury characteristics, causes and injury incidence. We identified players in the 30+/40+ league as a target group for injury prevention. Their injury incidence was significantly higher compared to players from other leagues; they were more likely to report a severe game injury; and they caused above-average injury costs. In addition, 30+/40+ league teams less frequently implemented preventive measures and injury prevention programmes than teams from other leagues. Changes in the incidence of injury in amateur soccer between 2004, 2008, and 2015 indicate that Swiss amateur soccer may have increased in intensity, including higher forces of impact and speeds. We observed an increase in the incidence of injuries requiring medical attention, of contact injuries during games, and of non-contact injuries during training. Furthermore, during games, the incidence of bone fractures and sprains as well as knee and upper limb injuries also increased during this period. In the 2015 survey we found that Swiss amateur soccer coaches are generally willing to implement preventive measures. However, only 22% of coaches implemented an existing prevention programme according to minimal standards. This proportion was the same as in the 2008 survey, although an additional prevention programme was available in 2015. Knee injuries were not only common in Swiss non-professional soccer, but they also had notable impact in terms of severity and costs of an injury. A significant increase of the incidence of knee injuries was found between 2004 and 2015. With respect to injury causes, the proportion of injuries caused by contact with an opponent and foul play was significantly higher during formal games than during formal training and informal play. Based on the referees’ assessment, in 27% of injuries foul play was the cause of injury during formal games. A detailed analysis of injury situations showed that being tackled by an opponent was associated with a higher likelihood of reporting a severe injury while foul play was not. Additionally, twisting and turning was a frequent cause of severe injuries and high injury costs. Conclusions The studies presented within this PhD thesis provide a detailed picture of injuries in Swiss non-professional soccer, which should form the basis for further improvements in injury prevention. New approaches are needed to increase the proper implementation of prevention programmes in Swiss amateur soccer in general and in individual risk groups such as 30+/40+ league players in particular. In addition, the reduction of contact and foul play injuries during games must be a central objective in the future. To this end, various measures must be considered, such as rule adjustments, stricter rule enforcement by referees, and less competitive ways of playing adapted to amateur soccer leagues