Rigidity
# Rigidity

Rigid or rigidity may refer to:

## Mathematics and physics

* 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

* 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

* Real rigidity, and nominal rigidity, the resistance of prices and wages to market changes in macroeconomics
* Ridgid, a brand of tools
