Standard anatomical position in human anatomy
- The standard anatomical position is the reference position for anatomical location terms.
- It is used to standardize the position of appendages in relation to the main body of the organism.
- In the standard anatomical position, the human body is standing erect and at rest.
- The limbs are placed in positions reminiscent of the supine position imposed on cadavers during autopsy.
- The feet are together or slightly separated, and the arms are rotated outward with palms forward.
Implications of limb positions in the standard anatomical position
- The positions of the limbs have important implications for directional terms in those appendages.
- The penis in the anatomical position is described in its erect position and lies against the abdomen.
- The dorsal surface of the penis is actually anterior when the penis is flaccid.
- Limb positions help avoid confusion in terminology when referring to the same organism in different postures.
- For example, even if the elbow is flexed, the hand remains distal to the shoulder.
Standard anatomical position of the skull (Frankfurt plane)
- The Frankfurt plane is the agreed-upon anatomical position of the human skull.
- It is a position in which the lower margins of the orbits and the upper margins of the ear canals lie in the same horizontal plane.
- The Frankfurt plane approximation is based on the position the head would be in if the subject were standing upright and facing forward.
- It is used for comparison of human skulls with those of other species, particularly hominids and primates.
- The Frankfurt plane is not considered the anatomical position for most non-primate species.
History of the Frankfurt plane
- The Frankfurt plane was established at the World Congress on Anthropology in Frankfurt am Main, Germany in 1884.
- It was decreed as the anatomical position of the human skull.
- The plane passes through the inferior margin of the left orbit and the superior margin of each ear canal.
- The alternate spelling 'Frankfort plane' is also widely used.
- The Frankfurt plane is also referred to as the auriculo-orbital plane.
Standard anatomical position in other animals
- For dogs, the standard anatomical position has the abdomen ventral with each paw standing on the supporting surface.
- The standard anatomical position may vary in different animal species.
- The Frankfurt plane can be used as a reference point in related fields, such as prosthodontics.
- The Frankfurt-Mandibular plane Angle (FMA) is the angle formed at the intersection of the Frankfurt plane with the mandibular plane.
- The standard anatomical position is important for comparative anatomy studies.
The standard anatomical position, or standard anatomical model, is the scientifically agreed upon reference position for anatomical location terms. Standard anatomical positions are used to standardise the position of appendages of animals with respect to the main body of the organism. In medical disciplines, all references to a location on or in the body are made based upon the standard anatomical position.
A straight position is assumed when describing a proximo-distal axis (towards or away from a point of attachment). This helps avoid confusion in terminology when referring to the same organism in different postures. For example, if the elbow is flexed, the hand remains distal to the shoulder even if it approaches the shoulder.