rotation (redirected from rotation fork)

rotation /ro·ta·tion/ (ro-ta´shun) the process of turning around an axis. In obstetrics, the turning of the fetal head (or presenting part) for proper orientation to the pelvic axis.ro´taryro´tatory

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optical rotation  the quality of certain optically active substances whereby the plane of polarized light is changed, so that it is rotated in an arc the length of which is characteristic of the substance.

van Ness rotation  fusion of the knee joint and rotation of the ankle to function as the knee; done to correct a congenitally missing femur.

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ro·ta·tion (r-tshn)

n.

1. The act or process of turning around a center or an axis.

2. Regular and uniform variation in a sequence or series, as in the recurrence of symptoms of a disease.

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rotation

[rōtā′shən]

Etymology: L, rotare

1 the gyration of a bone around its central axis, one of the four basic movements allowed by the various joints of the skeleton. The central axis may lie in a separate bone, as in the pivot formed by the dens of the axis around which the atlas turns. Some bones, such as the humerus, rotate around their own longitudinal axis. Alternatively, the axis of rotation may not be quite parallel to the long axis of the rotating bone, as in movement of the radius on the ulna during pronation and supination of the hand. Compare angular movement, circumduction, gliding.

2 a turning around an axis.

3 the turning of the fetal head to descend through the pelvis during birth.

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rotation,

n circular movement of a bone around its own axis.
Lateral and
medial rotation are directional referents.
Upward and
downward rotation refer only to the scapulae.

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rotation,

n 1. the act of turning about an axis or a center.
n 2. movement of a tooth around its longitudinal axis.

rotation center,

n See center, rotation.

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rotation

a state of having been pivoted around an axis. See also torsion, rotational.

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rotation flap graft

see pedicle graft.

rotation fork

an obstetrical instrument used in mares and cows. A 3 ft long rod with a crossbar handle and a two-pronged fork at the other end. The prongs have eyelets to which cord or canvas hobbles are attached. Two presenting limbs are threaded through these and the instrument pushed into the uterus to the body. Rotation of the bar handle helps to rotate the calf or foal, or uterus if it is closely applied. See also cammerer rotation fork.

pedal rotation

see pedal bone rotation.

rotation programs

alternation of crops (crop rotation), of grazing of pastures (paddock or field rotation), of bulls or rams running with breeding females (bull rotation), of anticoccidial agents to poultry or anthelmintics to sheep to avoid the development of resistance to the medication by the target organism. Rotational grazing of pastures is beneficial to pasture growth when livestock concentration is high, and aids in the control of helminth parasites by interrupting their life cycles.

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rotation

Movement around an axis Graduate education A period of time during which a medical student, or a physician in an early period of his training works in a particular service. See Audition rotation, Clinical rotation, Extern, Intern Obstetrics The turning of a fetus around its long axis such that the presenting part changes. See External rotation, Internal rotation, Limb rotation.