Prognosis
A 50-year follow-up study published in the Journal of the American Medical Association (2003) asserted the lifelong physical health, including cardiopulmonary and neurological functions, and mental health of people with idiopathic scoliosis are comparable to those of the general population. Scoliosis that interferes with normal systemic functions is "exceptional" and "rare", and "untreated [scoliosis] people had similar death rates and were just as functional and likely to lead productive lives 50 years after diagnosis as people with normal spines." In an earlier University of Iowa follow-up study, 91% of people with idiopathic scoliosis displayed normal pulmonary function, and their life expectancy was 2% less than that of the general population. Later (2006-) studies corroborate these findings, adding that they are "reassuring for the adult patient who has adolescent onset idiopathic scoliosis in approximately the 50–70° range." These modern landmark studies supersede earlier studies (e.g. Mankin-Graham-Schauk 1964) that did implicate moderate idiopathic scoliosis in impaired pulmonary function.Generally, the prognosis of scoliosis depends on the likelihood of progression. The general rules of progression are larger curves carry a higher risk of progression than smaller curves, and thoracic and double primary curves carry a higher risk of progression than single lumbar or thoracolumbar curves. In addition, people not having yet reached skeletal maturity have a higher likelihood of progression (i.e., if the person has not yet completed the adolescent growth spurt). Epidemiology
Scoliosis affects 2–3% of the United States population, which is equivalent to about five to nine million cases.
The nerve travels in the posterior compartment of the thigh behind (superficial to) the adductor magnus muscle, and is itself in front of (deep to) the long head of the biceps femoris muscle. At the popliteal fossa, the nerve divides into its two branches:: 532 
The tibial nerve, which travels down the posterior compartment of the leg into the foot
The common fibular nerve (also called the common peroneal nerve), which travels down the anterior and lateral compartments of the leg into the footThe sciatic nerve is the largest nerve in the human body. : 422–4

Development
Function
The sciatic nerve supplies sensation to the skin of the foot, as well as the entire lower leg (except for its inner side). Sensation to skin to the sole of the foot is provided by the tibial nerve, and the lower leg and upper surface of the foot via the common fibular nerve. : 422–4 The sciatic nerve also innervates muscles. In particular:: 422–4 
Via the tibial nerve, the muscles in the posterior compartment of the leg and sole of the foot (plantar aspect). Via the common fibular nerve, the muscles in the anterior and lateral compartments of the leg. Clinical significance
Sciatica
Pain caused by a compression or irritation of the sciatic nerve by a problem in the lower back is called sciatica. Common causes of sciatica include the following lower back and hip conditions:  spinal disc herniation, degenerative disc disease, lumbar spinal stenosis, spondylolisthesis, and piriformis syndrome. Other acute causes of sciatica include coughing, muscular hypertension, and sneezing.