Lower leg pain in athletes: know the difference

Calf muscle strain injuries are common across sports involving high-speed running or high volumes of running load, acceleration and deceleration - and also during fatiguing conditions of play or performance⁽¹⁾. Match-play incidences in football record 0.84 calf injuries per 100 hours, whereas rugby union risk ratios ranging from 0.98 to 5.85 per 100 hours across different playing positions⁽¹⁾.

Muscle strains occur commonly in the medial head of gastrocnemius, or near the musculotendinous junction see figure 1). However, the medial third of the fibres of soleus (as well as its aponeurosis) are equally prone to injury, which is thought to be due to excessive subtalar pronation⁽²⁾. The greatest risk factors for injury include an athlete’s age (rising with age), and also any history of previous injuries in this area⁽¹⁾. There are also associated risks with corresponding lower-limb soft tissue or joint injuries, as well as the preseason period, or the player having an increased BMI⁽¹⁾.

Figure 1: Anatomy of major calf muscles

Acute injury is associated with sudden localised pain, with an occasional ‘tearing’ sensation. As a rule of thumb, the degree of disability is a guide to the severity of pain experienced. Investigations are generally not required in this type of injury, although ultrasound and MRI can be useful in differentiating muscle strain versus contusion, if this is not clinically evident⁽³⁾. In this instance, a comprehensive grading system based on imaging has been devised to provide diagnostic clarity in sport (see table 1)⁽⁴⁾. It is worth highlighting that a history of persistent calf symptoms with no specific onset should alert the clinician to other possible causes.