Great Britain’s Katarina Johnson-Thompson pulled up during the 200-meter event because of a right calf strain. After falling, she was still able to pick herself up to finish the race limping but later on disqualified for leaving her lane when she fell down.The 28-year-old heptathlete had a first-place finish in the 100-meter hurdles earlier but has had to withdraw from the heptathlon due to the calf injury.
The calf muscles or triceps surae consists of the gastrocnemius, soleus, and plantaris, whose fibers converge just above the heel to form the Achilles tendon. Common mechanisms of injury include high-speed sprinting, jumping, sudden changes in direction,and landing stumbling or tripping.
MECHANISM OF INJURY: In running, calf strain occurs during high speed acceleration or sudden changes in direction. Movements that involve a sudden eccentric force can place excessive stress on the gastrocnemius and cause strain or rupture, as occurs during rapid push off or jumping when the ankle rapidly changes from a plantarflexed to a dorsiflexed position. This mechanism typically happens in tennis players and is termed “tennis leg” in which the medial head of the gastrocnemius is strained when the player suddenly extends his knee with the foot dorsiflexed (pointing up).
Similar to other strain injuries, such as hamstrings and adductor strains, being at a later age and having a previous calf strain injury puts you at a strong risk for future calf injuries. Of the calf muscles, the gastrocnemius is considered at high risk for strains because it crosses two joints, the knee and ankle, and has a high density of type-II fast twitch muscle fibers, which are the type of muscle fibers that fire more quickly and are specifically called for or recruited for activities that require more intensity, such as sprinting and heavy weightlifting. It being a two-jointed muscle is prone to excessive stretch, combined with rapid forceful contraction of the muscle fibers results in strain.
A history of quadriceps injury was implicated to be predictive of calf muscle injury, possibly because changes in the biomechanics occur that predispose athletes to injury in different muscle groups (Orchard, 2001). Other factors that may increase gastrocnemius muscle strain are fatigue, impaired muscular coordination, and impaired blood supply to the gastrocnemius with weakened musculotendinous unit. Failure of the muscle to relax can also cause stretching injury and muscle strain.
To prevent injuries, trainers, coaches, and therapists should always investigate these potential risk factors and once identified, they should be address and fix with appropriate treatment/preventive remedies.
Evidence shows that there are ways to prevent calf strain injuries and re-injuries.
A proper warm-up begins with mild aerobic activity such as walking, biking or slow jogging for 5-to-10 minutes. This is to increase blood flow to the muscles, which increases their temperature and makes the fibers more responsive to stretching.
Literature has previously established the importance of gastrocnemius flexibility in sprinting athletes, and therefore maximal power outputs over fast velocities, (see Reference). Tissue extensibility or flexibility is critical for sprinting as it is associated with maximum power output over high speed running, although it’s unclear whether or not this is associated with high risk. Dynamic stretching is preferred because, unlike with static stretching, it is not associated with strength or performance deficits as studies suggest that dynamic stretching may even increase acute muscular power, such as leg extension power.
Strengthening helps in improving muscle function, range of motion and mobility, increasing efficiency and performance as well as reducing fatigue, all of which can greatly reduce chances of injury. The benefits of targeted strengthening exercises have been documented, as it promote strengthening of the soft and bony structures. Strength training needs to targeted and specific, that is, strengthening the right muscle specific to its function relative to the condition where injury typically occurs. As calf strain is often associated with the weakness in the eccentric strength of the gastrocnemius, resistance exercises targeting eccentric strength, as well as strength endurance have been implicated in preventing future muscle strains.
A study has demonstrated the importance of gastrocnemius “fascicle length” in sprinting athletes as it relates to maximal power outputs over fast speed. This highlights the importance of gastrocnemius flexibility in evaluating risk of injury. A study suggests that a 5-minute localized vibration therapy used to increase muscle flexibility can effectively improve muscle flexibility without affecting strength, while improving performance.
CREDIT: Background image by Matthias Hangst/Getty Images