Which component of viscoelastic tissue is primarily responsible for creep under sustained load?

• A. Elastic portion
• B. Viscous portion
• C. Both portions equally
• D. None

Answer: (B)

Creep is the time-dependent deformation that occurs when a viscoelastic tissue is held under a constant load. This gradual change happens mainly because of the viscous portion, which behaves like a flow element that slowly deforms under sustained stress. The elastic portion responds immediately to the load and mostly recovers when the load is released, so it drives quick, reversible deformation rather than ongoing creep. In tissues, the viscous component allows gradual sliding and rearrangement at the microstructural level, such as fiber interfiber movement or fluid flow, which produces the progressive elongation you observe over time. So, under a sustained load, creep is primarily due to the viscous portion, while the elastic portion governs the initial deformation that snaps back when the load is removed.