Structural vs Functional Scoliosis: Scoliosis

Structural Scoliosis

Structural scoliosis is also called adolescent idiopathic (of no known cause) scoliosis. It’s generally considered more permanent. Commonly, the onset of structural scoliosis will begin between the ages of 10 and 15, mostly in girls. (But there are other situations.)

  • Structural scoliosis is the result of unequal growth of the two sides of the vertebral bodies.
  • Among structural scoliosis cases, 70% are idiopathic (of no known cause).
  • In the other 30%, it can be attributed to such causes as congenital conditions, an underlying disease such as as polio or cerebral palsy, or a trauma to the spine or ribs.
  • Structural scoliosis often occurs in adolescence with bones and muscles growing at different rates. This can lead to an imbalance on either side of the body and at the pelvis. There is often also a rotational element in this form of scoliosis which produces a hump in one side of the spine.
  • Structural scoliosis is considered more serious than functional scoliosis. It may require surgery.

Functional Scoliosis

Functional (or nonstructural) scoliosis is also called degenerative scoliosis. It results from a soft tissue asymmetry. It’s generally found in people over the age of 50 and may be connected to changes in vertebrae, discs and ligaments, osteoporosis and loss of bone density.

  • Functional scoliosis is more common and does not structurally alter the body. It affects only the back muscles.
  • It can be caused by poor posture or repeated unbalanced activities such as golf, tennis or carrying a bag on one side.
  • “Back Spasm Scoliosis” is another type of functional scoliosis caused by muscles on one side of the spine going into spasm which gives the appearance of scoliosis. By relieving the spasm of the muscles, the back and spine can return to normal. (Doug Keller)
  • Functional scoliosis may also have genetic or neurological causes such as cerebral palsy, congenital muscle weakness, or problems such as oteogenesis imperfecta where the bones are soft and easily deformed. (Loren M. Fishman)
  • “Recently loss of bone density has been shown to cause lateral deviations in the spine that may contribute to the onset of scoliosis in postmenopausal women.” (Baxter Bell MD)

Observation Technique to Differentiate

To determine whether a scoliosis is functional or structural, bend forward from the hips. If a lateral (side to side) curve visible in standing disappears in this position, the scoliosis is functional. If the curve remains, it is built into the ribs and spine, and the scoliosis is structural. – Elise Browning Miller