The central canal of the spine houses the spinal cord, protecting it. Foramen or “windows” in the spine allow nerve roots to exit the spinal cord to eventually become nerves that travel to all areas of the body. When the central canal or the foramen become narrowed, it is called stenosis. Stenosis is essentially a condition of “nerve root strangulation”. A nerve root under pressure cannot transmit information from brain to body, creating a host of different symptoms. The most common symptoms is muscle weakness in the arms and/or legs.