In a recent clash against the Melbourne Storm, the Brisbane Broncos endured a nightmare rarely seen in professional sport — in a single game. Two players, Adam Reynolds and Ezra Mam, went down in the same play.
Hamstring strains are the in running sports such as rugby league. will suffer the same injury again.
So why do they happen and what can be done to stop them?
Hamstrings are a huge issue for athletes
More than in sport occur during sprinting, while others occur during .
The danger point is usually the of sprinting: the split second before the foot strikes the ground when the leg is swinging forward at high speed.
At this moment, the hamstrings are contracting while also lengthening.
The hamstrings’ job is to slow the leg and prepare it for ground contact. This requires very — a combination that increases .
It is not just speed that is dangerous.
Using the recent Storm-Broncos game as an example, when Xavier Coates intercepted the ball, and Mam and Reynolds suddenly accelerated to chase him down, their hamstrings were actually stretched further and faster than if they were running at a steady pace, even at much higher speeds.
Think of your hamstrings : during constant speed running the muscles stretch gradually, but yank it suddenly (as during acceleration) and it stretches faster — making it more likely to snap.
In fact, while running at only half your top speed puts the same stretch on your hamstrings as running constantly at nearly 90% of your maximum speed.
How to reduce hamstring injury risk
While no strategy can completely eliminate risk, there is evidence that two approaches reduce hamstring injuries: sprinting and eccentric strength training.
involves exercises where the muscle lengthens under tension, such as slowly lowering a weight.
Eccentric training, particularly the Nordic hamstring exercise, can when done regularly.
This exercise puts the hamstrings under high force while they are lengthening, that make them more resilient.
may help protect against hamstring injury by preparing the muscles for the exact demands they face in competition.
But if athletes go long periods without sprinting, a sudden can greatly increase their risk.
Consistency is crucial
Eccentric training can within 2-3 weeks, mainly from (tiny building blocks inside each muscle fibre that allow it to contract and stretch).
This short-term (two to three weeks) change may not provide much real protection from injury.
However, with longer-term training (around nine weeks), , creating longer fibres that can better of sprinting.
This difference helps explain why short pre-season training blocks may be insufficient and why consistent eccentric training is needed to build lasting protection.
Eccentric training also increases strength by of the muscles.
are stronger and can cope better with the huge forces they face during sprinting.
These two changes — — appear to be the main reasons eccentric training cuts injury risk by half.
It’s also possible other changes play a role, like the muscles switching on more quickly or the tendons and connective tissues getting stronger but research in this area is still limited.
Challenges for athletes and teams
The protective changes from eccentric training are not permanent.
Fibre length and added sarcomeres begin to .
This is a major challenge in professional sport, where busy schedules and from eccentric exercise mean stick with these prevention strategies in-season.
The good news is to eccentric training, so soreness diminishes over time. Once players build up a tolerance to eccentric training, just may be enough to maintain the protective benefits without overloading athletes.
Teams that consistently use these exercises experience than those that don’t.
An issue that shouldn’t be ignored
Even with world-class sports science support, hamstring injuries are still the from training and competition in professional football codes.
Predicting and preventing hamstring injuries remains a challenge. But eccentric strength training and regular sprinting can provide protection.
Effective prevention requires not just using eccentric strength training exercises but doing them consistently, alongside careful management of load, recovery and other risk factors.
Putting this into practice in elite sport is difficult, which may help explain why .
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