INJURY PREVENTION

INJURY PROFILES IN PROFESSIONAL FOOTBALLERS

by Catrin Sheppard MSc, BSc, and Alan Hodson, head of medical education for the Football Association

Football is an increasingly popular sport with The Football Association (FA) Annual Review 2003/04 (1) documenting that there are 37,000 football clubs providing for 12 mil- lion players in England alone. Although this popularity is crucial to the development of the game, football is not without its health risks. Football players incur considerably more injuries than participants in sports such as rugby, hockey, cricket and cycling (2), with injury incidence in professional football shown to be around 1,000 times high- er than for industrial occupations deemed ‘high risk’ (3). This article is an overview of an FA Medical Research Programme - a comparison of injury profiles in profession- al footballers between the 1997-98 and 2003-04 seasons.

INTRODUCTION Over recent years, rule changes such as dangerous tackles from behind becoming punishable offences, have attempted to make the game safer (4); yet no objective data is available to determine the effect of such law changes. Previous authors (3,5,6,7,8) have reported the injury characteristics of individual football seasons, however only once have injury characteristics been compared between seasons (9). This information is valuable to determine whether or not current players are at an increased risk of injury compared to players competing during previous seasons. This may indicate to governing bodies, coaches and medical professionals the success of any injury-reduction interventions that have been implemented, and whether any interventions should be imple- mented in the future to reduce the risk of injury in professional football. Consequently, the aim of this study was to determine whether there were any differences in injury profiles between the 1997-98 and 2003-04 English football seasons.

STUDY DESIGN At the start of the 1997-98 and 2003-04 seasons, 91 and 87 of the 92 professional English league clubs (Premier and the three football leagues), respectively, agreed to participate in the study. Injuries were reported prospectively from 1st July 1997 to 31st May 1998 and from 1st July 2003 to 31st May 2004. All injuries were identified and recorded by medical practitioners at each club using specially designed audit questionnaire forms to standardise the information returned by each club. Injuries were defined as ones received during training or competition, which prevented the injured player from participating in normal training or competi- tion for at least 48 hours, excluding the day of injury. Absences from training or competition due to sickness, or injuries sustained outside football participation, were not reported. Injury severity was defined according to the length of absence from

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training/competition: slight (2-3 days); minor (4-7 days); moder- ate (8-28 days), or major (>28 days). Audit forms were returned monthly, according to when players returned to full training/com- petition. Re-injuries were classified as a recurrence of an injury, identical in nature, to the same anatomical location within the same competitive season.

STATISTICS In total 2,335 and 1,739 players were audited, with 3,294 and 2,540 injuries being recorded in 1997-98 and 2003-04 respective- ly. Over 60% of injuries occurred during matches in both the 1997-98 and 2003-04 seasons.

The 2003-04 season saw a significantly greater proportion of injuries occurring between 31-45 minutes, and 46-60 minutes of the games compared with 1997-98 (p<0.05 and p<0.001, respec- tively, Fig.1). This implies that an element of fatigue may con- tribute to injury occurrence immediately prior to half time, where- as players may have ‘cooled down’ slightly during the half-time break, thus pre-disposing them to injury when they return for the

Figure 1: Frequencies of injuries sustained at specific time inter- vals during matches in 1997-98 and 2003-04 seasons. Values shown are percentage of total injuries sustained each season.

second half.

Half time injuries The proportion of injuries sustained in the second half of match- es was significantly greater than the proportion of injuries sus- tained in the first half, in both the 1997-98 and 2003-04 seasons (p<0.001 and p<0.01, respectively). Maintaining activity levels during half time significantly improved sprint performance at the start of the second half compared with no activities (10) and pre- vents the decrease in muscle temperature that would normally occur during half time. This evidence suggests that performing football-specific activities at half time enhances second-half sprint performance, and may play a role in injury prevention.

Timing of injuries The time of the year when injuries occur has major implications for coaches and players alike. Significant differences were seen in the month of the season that injuries occurred (Fig.2), with the number of injuries reported in July 2003 being significantly lower than reported in July 1997 (p<0.01). This suggests pre-season

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