Rigid or rigidity may refer to:

Mathematics and physics

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  • Stiffness, the property of a solid body to resist deformation, which is sometimes referred to as rigidity
  • Structural rigidity, a mathematical theory of the stiffness of ensembles of rigid objects connected by hinges
  • Rigidity (electromagnetism), the resistance of a charged particle to deflection by a magnetic field
  • Rigidity (mathematics), a property of a collection of mathematical objects (for instance sets or functions)
  • Rigid body, in physics, a simplification of the concept of an object to allow for modelling
  • Rigid transformation, in mathematics, a rigid transformation preserves distances between every pair of points
  • Rigidity (chemistry), the tendency of a substance to retain/maintain their shape when subjected to outside force
  • (Modulus of) rigidity or shear modulus (material science), the tendency of a substance to retain/maintain their shape when subjected to outside force

Medicine

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  • Rigidity (neurology), an increase in muscle tone leading to a resistance to passive movement throughout the range of motion
  • Rigidity (psychology), an obstacle to problem solving which arises from over-dependence on prior experiences

Other uses

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