Poisson effect

(fluid mechanics) The deflection of a spinning projectile with right-handed spin to the right, and vice versa. Also known as cushion effect.

The dual effect that a compression load has on an object: the compression causes the object to become shorter in the direction of the compressive load and wider laterally. Thus, an intervertebral disc subjected to compression will shorten in the vertical dimension, but will bulge out laterally. For each different type of material, there is a specific ratio of strain in the axial direction to strain in the transverse direction; this is known as the Poisson ratio.