Hamstring injuries are one of the most common injuries in sports such as sprinting, and AFL football. The good news is that many of these injuries are preventable with some basic strength exercises which are done pre-season (and often throughout the season as well).
The simplest, most effective exercise is called the 'Nordic Curl'.
The Nordic Curl can be performed with or without a partner. The legs/ankles are secured and the athlete slowly leans forward, using the hamstrings to control the movement. When the athlete can't control the movement any longer, they reach out and 'catch' themselves on the ground.
So what research do we have to support the use of this exercise?
- In Danish Football (soccer), Players completed 2-3 sets of 5-12 repetitions, 1-3 times per week for 10 weeks in the preseason, and then continued once per week during the season. This lead to about an 85% reduction in recurrent hamstring injuries and 60% reduction in first time injuries. (Peterson, 2011)
- In amateur Australian Rules Football, players did 5 sessions only of Nordic curls - 3 pre-season and 2 during the season (they were very big sessions!). Hamstring injuries were reduced by about 70%. (Gabbe, 2006)
- In Australian Rules Football, poor eccentric hamstring strength is associated with increased risk of injury during the season. Nordic Curls increase eccentric strength. (Opar, 2014)
- A smaller study, but Norwegian soccer players used Nordic Curls for 10 weeks, with 2-3 sets of 8-12 weeks. This resulted in a reduction in hamstring injuries of about 50-60% (Engebretsen, 2008)
Practically, with athletes I work with, we use Nordic Curls roughly twice a week for at least 10-12 weeks in the pre-season, and then once a week as 'maintenance' for the rest of the season.
Of course Nordic Curls aren't a silver bullet for the prevention of hamstring injuries. There are several other risk factors that are modifiable. However they are an almost compulsory inclusion in sports with a high risk of hamstring injury, such as sprinting, Australian Rules Football and Soccer.