Calf Strain: Top Tips, Mechanisms and Management

Introduction:

Calf strains are a common injury among athletes and individuals engaged in physical activities. Understanding the anatomy, mechanisms of injury and the essential components of early stage management is important when recovering from injury. 

Anatomy and Function of the Calf:

The calf, a complex musculotendinous unit, primarily comprises two distinct muscles: the gastrocnemius and the soleus. These muscles are important for lower limb function, impacting locomotion, stability, and balance.

Gastrocnemius: Originates from the posterior aspect of the femur, has two heads; medial and lateral and inserts into the calcaneus (heel bone) via the Achilles tendon. This muscle is the prime mover in ankle plantar flexion (standing on tiptoes) and assists in knee flexion, as it crosses the back of the knee, as well as the ankle.

Soleus: Positioned beneath the gastrocnemius, originates from the tibia and fibula, inserting into the calcaneus via the Achilles tendon. Unlike the gastrocnemius, the soleus exclusively contributes to ankle plantar flexion, and its role becomes prominent during activities where the knee is flexed.

Mechanisms of Calf strain:

Calf strain typically occur as a result of overstretching or overloading the tissue, some common mechanisms include;

Eccentric Overload: Where the muscle lengthens, under tension, such as landing on your forefoot during running or jumping or when an athlete suddenly pushes off during acceleration or deceleration, the calf muscles must work eccentrically during these actions and if the calf is not conditioned for this kind of loading it can be easily overloaded.

Sudden, Forceful Contraction: Rapid and forceful calf muscle contractions, such as when sprinting or jumping, can cause a sudden tear in the muscle fibres due to the high tensile forces involved. These injuries can range from mild to severe, depending on the intensity of the contraction.

Previous Calf Injuries: A history of calf injuries can weaken the tissue and make it more susceptible to future tears. Scar tissue and poor healing and recovery from previous injuries may lead to reduced muscle resilience.

Conditioning: There are a large number of variants that can contribute to muscular deconditioning. Age, Weight, Strength all factors that affect the calf’s ability to tolerate load and generally be resilient. Lack of conditioning will lead the calf to be less strong and generally resilient to loads and repetitive strain, ultimately making the calf more susceptible to injury.

Mechanisms of Healing:

A Calf strain is no different from any other soft tissue injury and how it follows the normal mechanisms of healing:

Inflammatory Phase: The initial response to injury involves an inflammatory cascade. This phase is characterised by the release of pro-inflammatory cytokines, increased blood flow, and the recruitment of immune cells to the site of injury. Inflammation plays a crucial role in removing damaged tissue and initiating the healing process.

Proliferative Phase: During this phase, the body initiates the formation of new tissue. Fibroblasts synthesise collagen, which provides the structural framework for the healing tissue. Collagen cross-linking and alignment are essential for tissue strength.

Remodelling Phase: In the final phase of healing, the tissue undergoes remodelling. Collagen fibres reorganise, and the tissue gradually gains strength. This phase can last for several months and is influenced by factors such as load and activity.

Healing times will vary depending on size or grade of tear, which your physiotherapist will have a good rough idea of, typically it can vary from 10-14 days for a mild strain, 4-6 weeks for a more moderate strain and 8-12 weeks for a severe strain. Sleep, Nutrition, Age and Rehabilitation and Conditioning strategy, will ultimately affect both healing/recovery and return to sport timeframes. 

Early Stage Management

Early stage management of calf strains is crucial for efficient recovery and optimising the healing environment. 

Accurate Diagnosis: Begin by conducting a thorough assessment, including a detailed history, physical examination, distinguishing whether it’s likely the Gastrocnemius or the Soleus is important as well as ruling out other pathology. 

POLICE Protocol: The initial management should follow the POLICE protocol – Protection, Optimal Loading, Ice, Compression, Elevation.

Protection: Heel Raises in shoes/trainers, sometimes even Crutches in the early few days can help alleviate pain and continued strain on the damaged fibres may be necessary to protect the injured calf and optimise the healing environment as the body's cellular processes get to work.

Optimal Loading: This crosses over with Protection, however, although we want to protect the damaged tissue, our body responds well to the right amount of load, encouraging the tissue to repair well, maintaining as much strength as we can as the tissue healing process progresses. Complete rest or protection is not good for our body in general and things will begin to weaken further and atrophy if chronically under-stimulated. 

Ice and Compression: Ice can help with pain relief and is an inexpensive and quick modality which may have some impact on swelling as well. Compression is important for managing swelling, as this increases pressure within the venous return system and helps the body’s natural processes, flushing inflammation out and is a good alternative to medications. Anti-Inflammatory Medications (NSAIDs) can help manage pain and inflammation, but their use should be monitored and guided by a Dr and more recent evidence suggests NSAID like Ibuprofen should not be taken in the early days of a soft tissue injury as our inflammatory process is essential to optimise healing in the early stages.

Elevation: This crosses over with compression, as slightly elevating areas of the body that are inflamed (around 15 degrees) above the heart can help utilise gravity to encourage lymphatic drainage, helping the body to process and remove damaged cells and unnecessary inflammation.

Conclusion

Calf tears are a common injury and rehabilitating them should be fairly straightforward. However, they can often become a challenging injury to manage for both athlete’s and physiotherapists, especially when not managed well early. Understanding the anatomy and function of the Calf, not just in the sport and performance context is important when tailoring recovery and rehabilitation interventions to the specific needs of each patient and closely monitoring their progress is key to ensuring a successful return to function and minimising the risk of recurrence. 

References:

Eming, S. A., Hammerschmidt, M., Krieg, T., & Roers, A. (2009). Interrelation of immunity and tissue repair or regeneration. Seminars in Cell & Developmental Biology, 20(5), 517-527.

Frantz, C., Stewart, K. M., & Weaver, V. M. (2010). The extracellular matrix at a glance. Journal of Cell Science, 123(24), 4195-4200.

Fields, K.B., & Rigby, M.D. (2016). Muscular Calf Injuries in Runners. Current Sports Medicine Reports, 15(5), 320-324. doi:10.1249/JSR.0000000000000292.

Prakash, A., Entwisle, T., Schneider, M., Brukner, P., & Connell, D. (2018). Connective Tissue Injury in Calf Muscle Tears and Return to Play: MRI Correlation. British Journal of Sports Medicine, 52(14), 929. doi:10.1136/bjsports-2017-097798.