spinal segmental dysfunction refers to abnormal movement of a spinal motion
segment. The abnormal movement may be passive or active. A spinal motion
segment is defined as two adjacent vertebrae, the intervertebral disc between
them, and the ligaments which support them. A spinal segment may move to much
(hypermobile), may have limited movement (hypomobile), may move in an abnormal
pattern (paradoxical movement) or it may not move at all (immobile or fixed. A
normal spinal segment should have a little bounce detected with manual
palpation. A loss of normal spinal segment joint play is a form of spinal
segment hypomobility. Spinal segmental dysfunction
can be further classified by whether there is associated reactive paraspinal
muscle spasm when movement is evoked.
segment dysfunction can occur in individuals of all ages. There is no
predilection between males or females. Trauma to the spine from a simple sprain
strain to severe injury will cause a loss of normal intervertebral motion. Segmental
dysfunction is likely to occur in the presence of degenerative changes of the
spine therefore it is prevalent in elderly individuals.