This ailment occurs when the spinal canal begins to become narrow due to several factors which include; a herniated disc, excessive bone growth, or thickening ligaments and cartilage in the canal.  This narrowing of the spinal canal often aggravates the spinal cord as well as the nerve roots at the point where they branch out from the cord. The degeneration of tissues as the human body ages is why the ailment occurs most in individuals over the age of 50.  Spinal Stenosis affects the neck (cervical) and lower back (lumbar spine) and is characterized by pain, numbness, and weakness in the buttocks, legs, and feet.