What does the modulus of elasticity measure in biomechanics?

The modulus of elasticity is a fundamental mechanical property that quantifies a material's ability to deform elastically when subjected to an applied force. It represents the ratio of stress (force per unit area) to strain (deformation relative to the original length) in the linear elastic region of the stress-strain curve. When a material is within its elastic limit, it will return to its original shape when the force is removed, and the modulus of elasticity provides insight into how much a material will deform under a given load.

This concept is crucial in biomechanics because it helps predict how biological tissues, such as tendons, ligaments, and cartilage, will behave under various mechanical loads. Understanding a tissue's modulus of elasticity can inform designs for prosthetics, orthopedic devices, and rehabilitation strategies by ensuring that the materials used mimic the mechanical properties of the biological tissues they replace or interact with.

The other options refer to different characteristics of materials: wear resistance is related to durability; density is a measure of mass per unit volume; and thermal expansion concerns how a material changes size in response to temperature changes. These properties are important in their own right but do not directly relate to elastic deformation or the suitability of materials under mechanical stress in the context of biomechanics.