Regional Differences in Injury Incidence in European Professional Football

Walden M, Hagglund M, Orchard J, Kristenson K, and Ekstrand J. Scand J Med Sci Sports. 2011 [Epub Ahead of Print].

Traditionally, risk factors for injury have been categorized as either intrinsic (individual) or extrinsic (environmental). One risk factor which has not been reported on in depth is weather conditions. Therefore, Walden and colleagues completed a prospective cohort study to investigate regional differences in injury incidence in men’s professional football in Europe. Twenty-five top-level professional European football (soccer) clubs were divided into 2 regions (“northern” = 20, “southern” = 5 [Mediterranean]) according to climate type using the Koppen-Geiger classification system (based on average monthly temperature and precipitation). Injury data was collected by either the medical or coaching staff, over a “varying number of season from 2001-2002 to 2009-2010. Injuries were classified as traumatic (sudden onset and known cause) or overuse (insidious onset and no known cause) and were recorded as occurring either during a match (competitive or friendly match against another team) or training session (team training involving physical activity under the supervision of a coach). Injury severity was also recorded and was based on day(s) missed due to injury (minimal = 1-3 days, mild = 4-7 days, moderate = 8-28 days and severe = >28 days). Data was then used to calculate incidence rates (per 1000 exposure hours) and rate ratios (incidence of northern group/incidence of southern group). Results of the study demonstrated that teams in the “northern” region had “significantly higher incidences of injury overall and of both traumatic and overuse injuries.” Injuries categorized as mild to severe (>3 days missed due to injury) were also significantly higher in the “northern” region compared to the “southern” region. Interestingly, the incidence of noncontact ACL injuries was lower in the “northern” region (rates ratio = 0.43).

The results of this study suggest that injury rates are influenced by the differences in climates. This is an intriguing concept to clinicians. What if our athletes are more susceptible to a certain injury because of where your school is located? Then it would be logical to provide region-specific preventative approaches to guard against injuries. The authors of this article suggest that factors such as availability of outdoor facilities, regional differences in tactics, shoe-surface traction, and factors related to ground hardness could lead to higher ground reaction forces and thus lead to an explanation for the discrepancy in injury rates. Where are you located, and what have you found? Have you seen certain injuries with which you believe there is an environmental link? Do you see more injuries when the weather is changing, perhaps suggesting the weather playing a part? Let us know what you think?

Written by: Kyle Harris
Reviewed by: Jeffrey Driban 

Waldén M, Hägglund M, Orchard J, Kristenson K, & Ekstrand J (2011). Regional differences in injury incidence in European professional football. Scandinavian Journal of Medicine & Science in Sports PMID: 22092416