The hamstrings are a muscle group at the back of the leg and perform the actions of knee flexion and hip extension. The Biceps Femoris, Semimebranosis and Semitendinosis make up the hamstrings group.
Hamstring injuries are amongst the most common injuries in any sport that involves running. During the running motion, the hamstrings are required to work eccentrically to control knee extension as the leg swings through during the running action.
Recurrence rates of hamstring injuries remain high, and the biggest risk factor for a hamstring strain is previous injury. Other risk factors for hamstring strains include age and previous knee injury. Many people return to sport with a reduced eccentric strength of the hamstring muscles, putting them at further risk of recurrence of injury.
Preventing hamstring injuries through training
The concept of eccentric hamstrings training is a key one in both the consideration of prevention and rehabilitation. Due to the fact that the hamstrings cover two joints, both the hip and knee, exercises should be done to target both these regions.
The standard knee flexion gym machine, for example, does not challenge the long head of the biceps femoris sufficiently, and so is only challenging the knee aspects of the hamstrings.
Exercises such as Nordics or Romanian deadlifts are far superior in their use for prevention and rehabilitation of hamstring injuries due to the fact they offer multi-joint eccentric loading for the hamstrings.
There is evidence supporting the use of twice weekly eccentric hamstring training in the prevention of hamstring strains. Research in football has also shown a single dose of Nordics exercises per week was sufficient in reducing the incidence of hamstrings strains in comparison to previous seasons when this was not implemented.
Treating hamstring injuries
If you happen to have sustained a hamstring injury despite all your best prevention efforts, always consult with an experienced health professional to determine your treatment course.
Treatment usually involves a period of relative rest, manual muscle treatment and an extensive rehabilitation protocol involving strengthening the muscle with the emphasis on eccentric work.
As with anything, prevention is better than cure so make sure your weekly training schedule has some sort of eccentric hamstring work in it.
Many research papers have suggested Nordics to be a key exercise in hamstring injury prevention so give it a try in your next gym session.
Work with a partner who holds your ankles whilst you kneel down.
Tilt your body forward bringing your body towards the floor, all the while controlling the descent with your hamstrings.
Start off with 2-3 sets of 4 as you build up compliance.
Increase to sets of 8 reps as you feel ready and enjoy those bulletproof hamstrings!