In medicine, the lower extremity is called the leg. The leg starts at the buttocks and hip and runs through the thigh, knee joint, lower leg, ankle joint to the foot. The leg consists of numerous bones, muscles, tendons, ligaments, nerves and blood and lymph vessels. All these structures can become conspicuous due to injuries, incorrect strain, inflammations and tumors. Depending on the supposed cause of the symptoms, ultrasound examinations, X-rays, scintigraphies, magnetic resonance tomographies or computer tomographies of individual structures are made (e.g. MR knee joint, X-ray forefoot, CT ankle joint, skeletal scintigraphy with SPECT/CT).