This occurs because the spinal cord in a child with Spina bifida is low lying and tethered at the bottom. At the time of birth the mylomeningocele is separated from the skin but the spinal cord is still stuck in the same place. As the child begins to grow the spinal cord remains in the same place becoming stretched out causing the tight cord and the tethering at the end. With this type of tethering there is an interference with the blood supply to the nerves and body which can then cause the deterioration of the body causing orthopedic, neurological, and urological problems. With milder forms of Spina bifida such as Occulta, may be related to the degree of strain on the cord which can become worse with physical activity, injury, pregnancy, bone spurs, or spinal stenosis. The tethered cord in this case might not be diagnosed until adulthood when it worsens and can still cause neurological, orthopedic, and urological dysfunctions. Mechanism
Tethered spinal cord syndrome is a clinical entity which is manifested by progressive motor and sensory changes in:

legs
incontinence
back of leg pain
scoliosisIn order to understand the pathophysiology that is involved in a tethered spinal cord, the reduction/oxidation ratio has to be used in vivo of cytochrome alpha and alpha 3 to signal the oxidative metabolic functioning in humans. Studies have found that marked metabolic and electrophysiological susceptibility to hypoxic stress to the lumbar and sacral portion of the spinal cord under traction with various weights.
Like with the early-onset form, this disease form is linked to the Arnold–Chiari malformation, in which the brain is pulled or lowers into the top of the spine. Prognosis
The disorder progresses with age, but the aforementioned treatments can help prevent or sometimes relieve symptoms. With treatment, individuals with tethered spinal cord syndrome have a normal life expectancy. Studies have shown surgery can help improve low back pain, urinary symptoms leg weakness and walking distance. However, most neurological and motor impairments are irreversible. References
External links

National institute of Health page