Adolescent low back pain has been reported to present in more than 50% of school-age patients. Parents are often confused about the severity of the complaints and the child remains engaged in sports and other extracurricular activities. After months of pain and appropriate relief with anti-inflammatory medication, parents may evaluate their child’s condition. The first step is to analyze the cause of the adolescent’s low back pain. Clinical examination may provide information on the site of pain, muscle spasm, lumbar spine range of motion, N cord muscle tension, lower extremity muscle strength, reflexes, and sensation in the lower extremities. X-rays may suggest a number of potential diagnoses and will guide the physician to clarify an isthmus stress injury or fracture. After passing almost 8 years of age, any patient begins to experience abnormal growth and development of this particular part of the skeleton. Genetic weakness in this area of the skeleton has been found in specific ethnic groups, such as Alaskan Indians. It is also found in specific sports (gymnastics, excessive weight lifting) and may be problematic in susceptible populations. For the isthmus injury three stages. They include: stress reaction; fracture (isthmus fracture); and slippage. Stress reactions may result from excessive weight bearing or strain on the fracture during daily activities, sports, or the above activities. These symptoms include low back pain, stiffness, and tension in the N cord muscle. x-rays do not reveal any abnormalities. A bone scan can confirm an inflammatory response in the isthmus. Treatment consists of pain relief and restoration of flexibility to the spine. After several months, the majority of patients can regain most of their spinal motion.