mobility

1. The quality or state of being mobile.
2. The movement of people, as from one social group, class, or level to another: "There's been . . . restructuring of industry and downward mobility for Americans as a whole" (Lawrence W. Sherman).

Symbol u. The terminal speed of an ion in an electric field divided by the field strength.

The ease with which a joint or series of joints is able to move before being restricted by the surrounding structures. Joint mobility is determined by the ligaments, joint capsule, musculature, and the size and shape of the bones within the joint. See also flexibility and range of movement.

The loosening of a tooth or teeth. Mobility is an important diagnostic sign that may result not only from a decrease in root attachment or changes in the periodontal ligament but also from destruction of the gingival fiber apparatus and transseptal fibers.

n. a quality or capability of military forces that permits them to move from place to place while retaining the ability to fulfill their primary mission.

See the Introduction, Abbreviations and Pronunciation for further details.

A general term used to describe any kind of spatial movement; not solely migration, which involves a permanent change of residence, but also, for example, tourism, commuting, or studying away from home. These latter forms of movement have been classified as circulation. W. Zelinsky (Geog. Rev. 13) developed a mobility transition model which suggested that, as a region or nation develops, there are changes in mobility. Geographical mobility, initially restricted, increases greatly with development, until the point when sophisticated transport means that migration may be replaced by circulation (one might, for example, commute from Leeds to London, or take regular international flights instead of relocating), or when phones, faxes, and modems reduce the need to circulate.

1. (joint mobility) The ease with which an articulation, or series of articulations, is able to move before being restricted by surrounding structures. Mobility is difficult to measure. Sometimes measurements of the end-position achieved by the extremity of a limb or limb-segment are used to reflect mobility, but these measurements are dependent. on the positional relationships of other segments of the body. See also active mobility exercise, passive mobility exercise.

2. See social mobility.

(DOD, NATO) A quality or capability of military forces which permits them to move from place to place while retaining the ability to fulfill their primary mission.