Muscle injuries of the lower leg.

Muscle injuries of the lower leg are a common cause for time off from sports, and may also be a cause of disability in nonathletes who have a running or "pushing off" injury as part of their activities of daily living. Most injuries can be managed without imaging, but in selected cases advanced imaging techniques can demonstrate the exact site and extent of the injury and potentially modify rehabilitation and return to sports. In experienced hands ultrasonography can identify the location of muscle injuries as well as aid in hematoma aspiration. It is useful for excluding differential diagnoses such as deep vein thrombosis or Baker's cyst and may be superior for investigating certain conditions such as muscle hernia. Magnetic resonance imaging is more sensitive for injury to deeper muscles and dual injuries and is generally the modality of choice in elite athletes.