Torsion

When a torque tries to rotate a fixed object (that is, an object stopped from rotating by another torque, exerted by the suspension or mounting), the object might twist as a result. We call this deformation torsion. For small twists, the twist angle is proportional to the torque.

https://commons.wikimedia.org/wiki/File:Angle_torsion_cylindre.svg (CC BY-SA)