In a dramatic turn of events during a recent match against the Melbourne Storm, the Brisbane Broncos faced a rare and challenging scenario in professional sports: three players sustained hamstring injuries in a single game. Among them, Adam Reynolds and Ezra Mam were injured simultaneously during a critical play.
Hamstring strains are the most prevalent non-contact muscle injuries in running sports like rugby league, with statistics indicating that one in three players will experience a recurrence. This raises vital questions: why do these injuries occur so frequently, and how can they be prevented?
The Mechanics of Hamstring Injuries
Hamstring injuries predominantly occur during sprinting, accounting for over 80% of such incidents in sports. The critical moment is often the “late swing” phase of sprinting, just before the foot strikes the ground. During this phase, the hamstrings are tasked with slowing the leg and preparing it for ground contact, a process that requires them to contract while lengthening.
The recent Storm-Broncos game serves as a poignant example. When Xavier Coates intercepted the ball, Mam and Reynolds accelerated to catch him. This sudden acceleration stretched their hamstrings further and faster than a steady pace, increasing the likelihood of injury. To visualize, think of hamstrings as a rubber band: gradual stretching is manageable, but a sudden yank can cause it to snap.
Why Acceleration Matters
Acceleration, even at half of one’s top speed, can place the same strain on the hamstrings as running constantly at nearly 90% of maximum speed. This illustrates the significant risk associated with rapid changes in pace.
Strategies for Reducing Hamstring Injuries
While no method can entirely eliminate the risk of hamstring injuries, two approaches have shown promise: sprinting and eccentric strength training. Eccentric training involves exercises where the muscle lengthens under tension, such as slowly lowering a weight. The Nordic hamstring exercise, in particular, has been shown to reduce injuries by more than 50% when performed consistently.
This type of training induces structural and functional changes in the hamstrings, making them more resilient. Regular sprint training also prepares the muscles for the demands of competition, though sudden increases in sprinting load can elevate injury risk if athletes have not maintained consistent sprint training.
The Importance of Consistency
Eccentric training can lengthen muscle fibers within two to three weeks, primarily by stretching existing sarcomeres. However, this short-term change offers limited protection. Long-term training, around nine weeks, adds new sarcomeres, resulting in longer fibers that can better withstand the stresses of sprinting.
“Eccentric training cuts injury risk by half by increasing muscle fiber length and strength.”
Consistency in eccentric training is crucial, as the protective changes are not permanent. Muscle fiber length and added sarcomeres begin to regress within three weeks of stopping the exercises.
Challenges in Professional Sports
In professional sports, maintaining consistent eccentric training is challenging due to busy schedules and the muscle soreness these exercises can cause. However, muscles adapt quickly, and once athletes build a tolerance, as few as four Nordic reps per week may suffice to maintain benefits without overloading players.
Teams that consistently incorporate these exercises report fewer injuries compared to those that do not. Despite advancements in sports science, hamstring injuries remain the leading cause of time lost from training and competition in professional football codes.
The Path Forward
Predicting and preventing hamstring injuries continues to be a complex challenge. Nonetheless, eccentric strength training and regular sprinting offer significant protection. Effective prevention requires consistent application of these exercises, alongside careful management of training load, recovery, and other risk factors.
“Putting prevention strategies into practice in elite sports is difficult, which may explain why hamstring injury rates are not decreasing.”
As teams strive to reduce injury rates, the focus on consistent training and innovative prevention strategies remains critical. The ongoing research and adaptation of training programs will be essential in mitigating the impact of hamstring injuries in the future.
