The 11+ injury prevention programme decreases rate of hamstring strain injuries in male collegiate soccer players

Objectives To investigate if the 11+ injury prevention programme decreases the risk of hamstring injury and improves recovery time and determine whether compliance with the 11+ affects hamstring injury risk. Methods This study is a secondary analysis from a prospective cluster randomised controlled trial that included 65 National Collegiate Athletic Association (NCAA) division I and II men's soccer teams over the fall 2012 season. Thirty-one teams were randomised to the intervention group that were using the 11+ as their warm-up and 35 teams to the control group that continued to use their traditional warm-up. Each certified athletic trainer (ATC) collected data on demographics, hamstring injury (HSI), mechanism of injury, position, playing surface, time lost due to injury and compliance to the 11+ programme. Results The 11+ decreased the risk of HSI by 63% compared with the control group (RR=0.37, 95% CI 0.21 to 0.63). Difference in return to play after HSI between the control (9.4±11.2 days) and intervention groups (10.2±11.3 days) was not significant (p=0.8). High compliance (>2 or more doses on average per week) reduced the risk of HSI by 78% (RR=0.22, 95% CI 0.06 to 0.87) compared with low compliance (<1 dose on average per week), and moderate compliance (1 to <2 doses on average per week) decreased the risk of HSI by 67% (RR=0.33, 95% CI 0.11 to 0.97) compared with low compliance. There was no significant difference between high and moderate compliance. Conclusion The 11+ decreased the risk of HSI by 63% but did not improve recovery time. High to moderate compliance is essential and makes the programme more effective at reducing HSI.