Hamstring strain injury is known to be the most common injury in soccer. The injury usually occurs during the later stages of each half in a soccer match-play due to fatigue factors. The distance covered at high speed by the players is reduced by 5-10% in the first 5-15 minutes of the second half of the game.
Identifying the biomechanical aetiological risk factors can enhance hamstring strain injury prevention. During the half-time interval in soccer, players frequently perform a passive recovery by sitting on the bench while receiving tactical instructions by the mangers and coaches. During the 15 minutes half-time interval the body temperature has been shown to decrease by ~1.1 ˚C and muscle temperature to decrease by ~1.5 - ~2 ˚C. Therefore, the muscles will have to work harder during the second-half of the game to increase the blood flow to the working muscles. This means more energy is used causing the muscles to fatigue.
In elite soccer, players usually tend to warm-up for 25-30 minutes prior to the match. This is done to prepare the players for the upcoming physical activity. This helps to increase temperature and blood flow to the working muscles. Increase in muscle temperature generates a greater blood flow through active tissue which encourages the separation of oxygen from haemoglobin and provides a protective mechanism to muscle by requiring a greater length of stretch and force to produce a tear in the warmed muscle.
Following a moderate-intensity (average HR ~135 beatsmin-1 or ~70% of the peak HR reached during the game) active re-warm-up for the final 7 minutes of the half-time interval, enhances player's performance by increasing the number of sprints and high-speed running performed by players during the second half. Previous research also shows that it increases dynamic strength performances. Therefore, this may reduce the risk of hamstring strain injuries in soccer during the latter stages of the game.
The Poster below shows the thesis carried out by Shad Aldeka during his undergraduate degree in BSc (Hons) Sports Therapy. Shad investigated the influence of half-time warm-up on hamstring strength measures in soccer.
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