The hamstrings are made up of three muscles; biceps femoris, semimembranosus and semitendinosus, with the biceps femoris being the most commonly injured component during sprinting. The three components of the hamstring muscle all originate from the pelvis and attach below the knee, which means they cross both the hip and knee joint – which has important implications in both the injury mechanism and the optimal rehabilitation protocol.
During sprinting the hamstrings, or biceps femoris most commonly as previously mentioned, are usually injured during the terminal swing phase, or the eccentric deceleration portion of the movement. In more simple terms this means that when you’re sprinting as your leading leg forcefully extends forwards and the knee straightens, the hamstrings are working maximally to decelerate the lower leg whilst they are simultaneously lengthening. When this is combined with contact sports we then often see a situation, common in AFL, where the athlete is sprinting and they’re pushed from behind in their back leading to a perfect storm where the hamstring is working eccentrically whilst being lengthened at BOTH ends of the muscle, which doesn’t usually end well for the hamstring!
When returning an athlete to competition there should be strong emphasis on strengthening the hamstrings eccentrically, returning the muscle to pre injury extensibility, re-educating proper biomechanics/movement patterns, strengthening core/pelvic stabilisation musculature and on normalising the ratio of hamstring to quadriceps strength. Whilst this is out of the realm of self-treatment for most athletes, requiring the aid of a professional to ensure the quickest possible recovery with the least chance of re-injury, there is something that athletes of all ages and skill levels can apply to their training to help prevent hamstring injury; ECCENTRIC STRENGTHENING EXERCISES!
The most popular, and my personal favourite with my athletes, is of course the Nordic Hamstring Curl. This exercise involves starting in high kneel, with the ankles fixed or being held by a partner, with the athlete slowly, and controlled, lowering themselves to the ground with all of the movement occurring at the knee join, ie. Keeping the hips straight throughout the movement – try it, it’s a lot harder than it looks! But as the expression goes, often the things that we find the hardest are the most beneficial, nothing worth having ever comes easy; and having bullet proof hamstrings is something that the majority of athletes would desire!
So if after completing an eccentric strengthening injury prevention program for your hamstrings you are still unlucky enough to find yourself on the wrong end of an injury, ensure that your physiotherapist is experienced with the comprehensive rehabilitation of these injuries in athletes and ticks off all the points made above!