Refers to the property of being able to bend and stretch, often used in technical or physical contexts. Related to the verb 屈伸する (to bend and stretch).
See also: 屈伸
This material has high elasticity.
I stretch to maintain the flexibility of my joints.
弾性 is a more common word for elasticity, especially in physics. 屈伸性 emphasizes the bending and stretching aspect.
Compound of 屈伸 (bending and stretching) + 性 (property, quality). The exact historical derivation is uncertain, but the components are transparent.