Somatic dysfunction is an Osteopathic concept that refers to impaired functioning of the somatic system with or without any significant disease process. It is akin to irritable bowel syndrome in Gastroenterology, epilepsy in Neurology, and dysrhythmia in a structurally normal heart.
Somatic dysfunction has been defined as "impaired or altered function of related components of the body framework system: skeletal, arthrodial, and myofascial structures, and related vascular, lymphatic, and neural elements. It is characterised by positional asymmetry, restricted range of motion, tissue texture abnormalities, and/or tenderness."
The principles of dysfunction diagnosis is based on the diagnostic triad - ART or TART depending if tenderness is added.
- T: Tissue texture changes. Palpation is done in a layered approach.
- A: Asymmetry of form of function of related parts of the somatic system. Comparisons are made of paired structures. Skeletal asymmetry may have an influence on functional asymmetry.
- R: Range of motion whether normal, increased, or decreased. The usual finding is of decreased ROM in somatic dysfunction. The motion is assessed for pathological and anatomical barriers and endfeel.
- (T): Tenderness on palpation.
It is said that acute somatic dysfunction is characterised by "pain, erythema, a palpable sense of relative warmth, moisture and bogginess, vasodilation, oedema, tenderness, and tissue contraction"
It is said that chronic somatic dysfunction is characterised by itching, paraesthesias, palpable sense of tissue dryness, coolness, tissue contracture, fibrosis, tenderness, and pallor"
Type I somatic dysfunction: a group dysfunction of the thoracic and lumbar vertebrae. The vertebrae are neutral in the sagittal plane but are sidebent and rotated in opposite directions (e.g. sidebent right and rotated left or vice versa)
Type II somatic dysfunction: a single segmental dysfunction of the thoracic or lumbar vertebrae. The vertebrae is significantly flexed or extended and is sidebent and rotated in the same direction (e.g. sidebent right and rotated right or vice versa)