People often talk about how many bones there are in your feet: 26 bones in each foot, 25% of your bodyâs bones are found in your feet, etc., etc. But your foot isnât just a bag of bonesâthere are muscles in those feet, and they can get injured, too. For example, thereâs your abductor hallucis muscle.he abductor hallucis muscle! This nifty little muscle starts at your calcaneous, or heel bone, runs along the arch, and then slides into the side of your big toe. It helps you move and flex your big toe, and holds up the arch of your foot.
Datum definition, a single piece of information, as a fact, statistic, or code; an item of data. See more.
A vertical datum is used for measuring the elevations of points on the earth's surface. They are used as a reference for specifying heights. Vertical datums are either tidal, based on sea levels, or geodetic, based on the same ellipsoid models of the earth used for computing horizontal datums.orizontal datums are used for describing a point on the earth 's surface, in latitude and longitude or another coordinate system. Vertical datums measure elevations or depths. In engineering and drafting, a datum is a reference point, surface, or axis on an object against which measurements are made.