We’ve all seen it at one point or another. It typically happens on the first day of pre-season training camp while testing 40-yard dashes. About 20 yards in, he pulls up in agonizing pain and grabs the back of his thigh like he’d just been shot by a sniper. If you’re lucky it’s just a hamstring strain or bad cramp. If you’re not so lucky, you may have lost this athlete for the rest of the season.
Hamstring injuries are one of the most prevalent injuries that occur in sports that involve sprinting. This includes track running and all field and court sports. During sprinting, the hamstrings contract concentrically to powerfully extend the hip and help propel the body forward. This then results in a very high speed eccentric hamstring contraction shortly before foot strike. It is often this part of the stride where hamstring injuries occur.
Understanding that eccentric hamstring strength is essential for reducing hamstring injury potential, great interest and attention has been given to the Nordic hamstring curl exercise (also referred to as partner glute-ham raises). This exercise involves having the feet anchored to the floor by a partner or apparatus while the trainee is in a kneeling position. They begin the movement by extending the hips forward while maintaining good spinal alignment and slowly lower themselves to the ground.
To determine the effectiveness of this exercise for reducing hamstring injuries, van der Horst et al. (2015) performed a study that was just pulished ahead of print in the American Journal of Sports Medicine. They investigated the preventative effects of Nordic hamstring curl training on the occurrence and severity of hamstring injuries over a competitive season in amateur soccer players. Nearly 600 male players (age = ~24 years) were randomly divided into an intervention group and a control group. The intervention group were provided with a program to follow for Nordic hamstring curls throughout the season (25 total workouts). The control group simply performed routine soccer practices.
The results showed that over the course of the season, 38 hamstring injuries occurred, affecting 26 of 579 athletes. Most of the injuries occurred during matches. Injury occurrence rate was significantly higher in the control group compared to the intervention group (odds ratio = 0.282). Injury severity was not different among the groups. Athlete compliance to the exercise protocol in the intervention group was >90%.
These results support previous work that has been done in other sports groups. It’s quite clear that eccentric hamstring strength is an important component to an overall strength and conditioning program to reduce hamstring injury risk in athletes.
van der Horst, N., Smits, D. W., Petersen, J., Goedhart, E., & Backx, F. (2015). The preventive effect of the nordic hamstring exercise on hamstring injuries in amateur soccer players: a randomized controlled trial. Am J Sports Med. Ahead of print.