New research, published in the American Journal of Sports Medicine this month, has demonstrated that male high school soccer players are more likely to suffer a hamstring strain than their female counterparts.
The study was undertaken at the UVA-Health South Sports Medicine and Rehabilitation Center in Charlottesville, Virginia. The authors used data gathered from the National Collegiate Athletic Association’s (NCAA) Injury Surveillance System (ISS) regarding all hamstring strain and rupture injuries in male and female soccer players between 2004 and 2009. The data was compared for injury rates between sexes, as well as the between injuries sustained in training or during a match and during pre or in-season.
The results demonstrated that men are 64% more likely to sustain a hamstring strain than women, in practice or competition. There were no differences between the genders during pre-season, but men were significantly more likely to suffer a hamstring injury during the in-season than women. Men are also more likely to suffer recurrent hamstring injuries.
Why is this?
Why hamstring strains occur so frequently is a bit of a mystery. Inadequate flexibility, lack of warm-up, reduced strength and muscle fatigue are possible risk factors for hamstring injury, as is diminished eccentric neuromuscular strength.
Whilst warming up and stretching etc can help to prevent such an injury, hamstring strains often occur part-way through a match when the muscles are already warm and flexible. However, they occur regularly in professional sports people who have medical teams to help them with flexibility, strength, endurance and rehab to ensure they are in the best possible shape, so it is hard to imagine that these are the main factors.
Out of these possible factors, the difference in occurrence between men and women is most likely to be down to flexibility. It has been proven that in general, women are around 7% more flexible in their joints than men. Increased flexibility also helps with neuromuscular co-ordination, reducing the risk to female athletes even further.
Whilst this is not guaranteed to be the only cause of a males increased risk, experts agree that is seems to be the most likely:
“In terms of the muscle mechanics, I don’t know if there is any gender difference there. But I know that probably females are more flexible. That means that during the same movement, the male may have a higher (chance of) muscle strain”
Bing Yu, from the physical therapy division at the University of North Carolina at Chapel Hill.
The lesson for male soccer players (and other athletes who are prone to this injury) is to focus on hamstring flexibility. A ‘normal’ range of motion for hip flexion (which can be limited by hamstring tension) is 80°, whilst athletes should be looking more for 90°. If you cannot lie on your back and raise one leg straight up to the ceiling, hamstring stretching is recommended.
In order to actually increase the flexibility of a muscle group, stretching before and after exercise alone is not sufficient. Stretches should be performed at least 3 times a day, holding each stretch for 30 seconds and repeating 2-3 times. The hamstrings can also be stretched with both the knee straight and the knee bent. Both should be performed in each stretching session.
Here is an example hamstring stretch:
Hold this stretch for 30 seconds and then switch legs. Repeat this another 1-2 times per leg, ensuring you can feel a constant and comfortably stretching sensation. This should not cause any pain.
Next, perform the same exercise, but with the knee a little bent. This will move the stretching sensation from the lower part of the hamstrings, up to the higher part, below the buttock. Again, perform this 2-3 times per leg.