| unit of force | CGS system: dyne, FPS system: poundal, MKS system: newton,SI: newton. (05 Mar 2000) |
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| force | <physics> Rate of change of momentum with time. Forces are said to cause accelerations via f = ma (Newton's law). There are four primary forces known presently: the gravitational, electromagnetic, weak nuclear, and strong nuclear forces. The gravitational and electromagnetic forces are long-range (dropping as 1/distance^2), while the nuclear forces are short range (effective only within nuclei, distances on the order of 10^-15 metres). The electromagnetic force is much stronger than the gravitational force, but is generally cancelled over large distances because of the balance of positive and negative charges. See: momentum. (04 Apr 1998) |
| force of infection | <epidemiology> The per capita rate at which susceptibles are infected. (05 Dec 1998) |
| force of mastication | The motive force created by the dynamic action of the muscles during the physiologic act of mastication. Synonym: biting strength, masticatory force. (05 Mar 2000) |
| force platform | A device used to measure the strength, symmetry, and latency of compensatory postural movements when visual, vestibular, and somatosensory stimuli are varied. (05 Mar 2000) |
| force pump | <machinery> A pump having a solid piston, or plunger, for drawing and forcing a liquid, as water, through the valves; in distinction from a pump having a bucket, or valved piston. A pump adapted for delivering water at a considerable height above the pump, or under a considerable pressure; in distinction from one which lifts the water only to the top of the pump or delivers it through a spout. Source: Websters Dictionary (01 Mar 1998) |
| force-velocity curve | The relationship between isotonic velocity of shortening and afterload for a contracting muscle. (05 Mar 2000) |
| lorentz force | <physics> Total electromagnetic force on a charged particle moving in electric & magnetic fields. F = q(E + (v/c)xB). See: force, cross product, charge, velocity, and relevant variable symbols. (09 Oct 1997) |
| adult pseudohypertrophic muscular dystrophy | Muscular dystrophy of late onset, often in the second or third decade, with relatively mild course; X-linked recessive inheritance; perhaps allelic with Duchenne's dystrophy, but milder and not a genetic lethal. Compare: Duchenne dystrophy. Synonym: Becker type tardive muscular dystrophy. (05 Mar 2000) |
| Becker's muscular dystrophy | An X-linked inherited disorder characterised by slowly progressive muscle weakness of the legs and pelvis. Other symptoms and findings include increased difficulty walking, intellectual retardation, fatigue and pseudohypertrophy of the calf muscles. (27 Sep 1997) |
| Becker type muscular dystrophy | A muscular dystrophy that has many of the clinical features of Duchenne muscular dystrophy e.g., symmetrical involvement of first the pelvicrural muscles and then the pectoral girdle and proximal upper extremity muscles; pseudohypertrophy, especially of the calf muscles but with a much later age of onset (35-45 years), and more benign course. X-linked inheritance. (05 Mar 2000) |
| Becker type tardive muscular dystrophy | Muscular dystrophy of late onset, often in the second or third decade, with relatively mild course; X-linked recessive inheritance; perhaps allelic with Duchenne's dystrophy, but milder and not a genetic lethal. Compare: Duchenne dystrophy. Synonym: Becker type tardive muscular dystrophy. (05 Mar 2000) |
| benign pseudohypertrophic muscular dystrophy | <neurology> An X-linked inherited disorder characterised by slowly progressive muscle weakness of the legs and pelvis. Other symptoms and findings include increased difficulty walking, intellectual retardation, fatigue and pseudohypertrophy of the calf muscles. (06 Aug 1998) |
| pelvofemoral muscular dystrophy | One of the less well-defined types of muscular dystrophy, probably heterogenous in nature. Onset usually in childhood or early adulthood and both sexes affected. Characterised by weakness and wasting, usually symmetrical, of the pelvic girdle muscles, the shoulder girdle muscles, or both, but not the facial muscles. Muscle pseudohypertrophy, heart involvement, and mental retardation are absent. Variable inheritance. Synonym: Leyden-Mobius muscular dystrophy, pelvofemoral muscular dystrophy, scapulohumeral muscular dystrophy. (05 Mar 2000) |
| childhood muscular dystrophy | The most common childhood muscular dystrophy, with onset usually before age 6. Characterised by symmetrical weakness and wasting of first the pelvic and crural muscles and then the pectoral and proximal upper extremity muscles; pseudohypertrophy of some muscles, especially the calf; heart involvement; sometimes mild mental retardation; progressive course and early death, usually in adolescence. X-linked inheritance (affects males and transmitted by females). Synonym: childhood muscular dystrophy, Duchenne's disease, pseudohypertrophic muscular dystrophy. (05 Mar 2000) |