The aims of this thesis were to study the incidence, severity and pattern of injury in male and female elite football players; to study time trends in injury risk; to identify risk factors for injury; and to test the effectiveness of an intervention programme aimed at preventing re-injury.
All studies followed a prospective design using standardised definitions and data collection forms. Individual training and match exposure was registered for all players participating. Time loss injuries were documented by each team’s medical staff.
The amount of training increased by 68% between the 1982 and 2001 Swedish top male division seasons, reflecting the shift from semi-professionalism to full professionalism. No difference in injury incidence or injury severity was found between seasons. The injury incidence was 4.6 vs. 5.2/1000 training hours and 20.6 vs. 25.9/1000 match hours. The incidence of severe injury (absence >4 weeks) was 0.8/1000 hours in both seasons.
The Swedish and Danish top male divisions were followed during the spring season of 2001. A higher risk for training injury (11.8 vs. 6.0/1000 hours, p<0.01) and severe injury (1.8 vs. 0.7/1000 hours, p=0.002) was observed among the Danish players. Re-injury accounted for 30% and 24% of injuries in Denmark and Sweden respectively.
The Swedish top male division was studied over two consecutive seasons, 2001 and 2002, and comparison of training and match injury incidences between seasons showed similar results. Players who were injured in the 2001 season were at greater risk for injury in the following season compared to non-injured players (relative risk 2.7; 95% CI 1.7-4.3). Players with a previous hamstring injury, groin injury and knee joint trauma were two to three times more likely to suffer an identical injury to the same limb in the following season, but no such relationship was found for ankle sprain. Age was not associated with an increased injury risk.
The effectiveness of a coach-controlled rehabilitation programme on the rate of re-injury was studied in a randomised controlled trial at amateur male level. In the control group, 23 of 79 injured players suffered a recurrence during the season compared to 10 of 90 players in the intervention group. There was a 75% lower re-injury risk in the intervention group for lower limb injuries (relative risk 0.25; 95% CI 0.11-0.57). The preventive effect was greatest during the first weeks after return to play.
Both the male and female Swedish top divisions were followed during the 2005 season. Male elite players had a higher risk for training injury (4.7 vs. 3.8/1000 hours, p<0.05) and match injury (28.1 vs. 16.1/1000 hours, p<0.001) than women. However, no difference was observed in the rate of severe injury (0.7/1000 hours in both groups). The thigh was the most common site of injury in both men and women, while injury to the hip/groin was more frequent in men and to the knee in women. Knee sprain accounted for 31% and 37% of the time lost from training and match play in men and women respectively