| knuckle | 1. The joint of a finger, particularly when made prominent by the closing of the fingers. 2. The kneejoint, or middle joint, of either leg of a quadruped, especially of a calf; formerly used of the kneejoint of a human being. "With weary knuckles on thy brim she kneeled sadly down." (Golding) 3. The joint of a plant. 4. <mechanics> The joining pars of a hinge through which the pin or rivet passes; a knuckle joint. 5. A convex portion of a vessel's figure where a sudden change of shape occurs, as in a canal boat, where a nearly vertical side joins a nearly flat bottom. 6. A contrivance, usually of brass or iron, and furnished with points, worn to protect the hand, to add force to a blow, and to disfigure the person struck; as, brass knuckles; called also knuckle duster. Knuckle joint, the lower part of a leg of veal, from the line of the body to the knuckle. Origin: OE. Knokel, knokil, AS. Cuncel; akin to D. Knokkel, OFries. Knokele, knokle, G. Knochel, Sw. Knoge, Dan. Knokkel, G. Knochen bone, and perh. To E. Knock. Source: Websters Dictionary (01 Mar 1998) |
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| knuckle pads | An autosomal dominant trait, in which thick pad's of skin appear over the proximal phalangeal joints; occasionally associated with leukonychia and deafness or Dupuytren's contracture, a callus reaction in persons predisposed to producing callus and as the result of occupational or self-inflicted trauma. (05 Mar 2000) |
| knuckle sign | <radiology> Seen in pulmonary embolism, abrupt tapering of an occluded vessel distally (12 Dec 1998) |
| aortic knuckle | The contour of the aortic arch protruding from the mediastinal silhouette in an anteroposterior (AP) radiograph of the chest. (05 Mar 2000) |
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| cervical aortic knuckle | An anomalous aortic arch in which the aorta extends into the neck and forms an anteroposterior arch, which may be as high as the hyoid bone; the common carotid artery of one side is given off from the summit of the arch, and the common carotid of the other side arises from the more proximal part of the aorta; the pulsating arch may be mistaken for an aneurysm, but the radial pulses are equal. (05 Mar 2000) |