A limp is a type of asymmetric abnormality of the gait. Limping may be caused by pain, weakness, neuromuscular imbalance, or a skeletal deformity. The most common underlying cause of a painful limp is physical trauma; however, in the absence of trauma, other serious causes, such as septic arthritis or slipped capital femoral epiphysis, may be present. The diagnostic approach involves ruling out potentially serious causes via the use of X-rays, blood tests, and sometimes joint aspiration. Initial treatment involves pain management. A limp is the presenting problem in about 4% of children who visit hospital emergency departments.