Target Muscle/s: Hamstrings
Sets & Reps: 5-10 reps
Tempo: Eccentric: slow, controlled lengthening of muscle
Frequency: Twice a week strength training program (or as advised if part of rehab plan)
Hamstring strains are notorious in all sports, but the mechanism of injury in distance running is slightly different. In football & rugby, most hamstring injuries are caused by sudden sprints; in dance & martial arts, injury is typically caused by a sudden need for extreme flexibility (just as in a sliding tackle in football). In distance running, there is rarely a need for sudden sprints or extreme flexibility. The point of greatest hamstring load is instead reached every time your knee swings in front of you prior to foot landing. At this moment, the hamstring muscles (located on the back of the upper leg) work hard to control the straightening of the knee, and they do this by decelerating the rate at which they lengthen. It is not lack of flexibility that puts the hamstrings at risk of injury, it’s lack of strength whilst they lengthen, something we call eccentric strength.
The easiest way to picture the eccentric action a hamstring muscle is imagine yourself lying face down on a hamstring curl machine. As you raise your heels towards your bottom to lift the weight, the hamstrings shorten. This is called a concentric contraction. Now slowly lower your heels (and the weight) back down – the hamstrings are now working hard as they lengthen and control the lowering of the weight. It is this eccentric contraction that mimics the demand on the hamstrings during running, Research suggests that the Nordic Hamstring Curl exercise is a particularly effective way to improve eccentric strength of the hamstrings and therefore reduce risk of injury.
WARNING: Start this exercise gently; do not try and lower yourself all the way to the floor. The safest way to start is perform them in front of a wall or heavy box (see our online video) and slowly increase the distance. Use the wall to push yourself back to start position and aim to initially do no more than 5 to 10 reps. Performed properly, the Nordic Hamstring Curl can be an excellent exercise, but take on too much too soon and you run serious risk of a hamstring strain.
- Kneel down opposite a wall or box and have your partner hold your ankles (or alternatively find a way to immobilise your feet). For the warm up set (especially if you have never done this exercise before) make sure the wall/box is close to you.
- Keeping your waist & back straight, slowly lower your body towards the wall/box in a controlled fashion by bending at the knees. By resisting any bending at the waist you will feel the hamstrings in the back of the upper legs immediately tense as they control & decelerate the movement, i.e. work eccentrically.
- Once you reach the wall/box, push yourself back to the start position and repeat. Do not try and pull yourself back up to start position with no hands. Save this for a few weeks time when your hamstrings have become stronger.
- If you can comfortably perform ten repetitions, progress the difficulty by increasing the distance slightly between you and the wall/box. Be aware that just a slight increase can make the final part of the exercise surprisingly more difficult.
Nordic Curls can be very useful in the later stages of rehabbing hamstring injury. In the earlier stages you will need to perform less strenuous exercises like bridges and light deadlifts, but towards the end of your rehab some Nordic Curls may be just the right thing to prepare you for a return to running, especially uphill runs, sprints and intervals where the demand on the hamstrings is greater. Whether you are recovering from a hamstring strain or looking to reduce risk of future injury, be sure to include some suitably graded eccentric hamstring strength training into your week.
Matt Phillips is a Running Injury Specialist & Video Gait Analyst at StrideUK & Studio57clinic in Sussex. Follow Matt on Twitter: @sportinjurymatt