Athletic injuries in the leg may be due to anatomic anomaly or sudden explosive movements, but most are overuse injuries. Although they may occur with any type of athletic activity, most are associated with running, whether recreational or high performance. It is difficult to identify the specific prevalence or incidence of these injuries because many athletes do not seek medical attention and because, although the pathoanatomy of these conditions is unique, their clinical presentations may overlap. Therefore, a careful history and physical examination may help delineate a specific entity and guide the selection of appropriate diagnostic tests. Treatment plans must be individualized to this specific diagnosis and patient. To prevent recurrence, training errors must be carefully identified and corrected, and a gradual, programmed return to training and sport-specific activity is indicated.