What term describes the decrease in stress that occurs when a constant strain is applied to skin over time?

What term describes the decrease in stress that occurs when a constant strain is applied to skin over time?

• A. Stress relaxation
• B. Creep
• C. Hysteresis
• D. Elastic rebound

Answer: (A)

The concept being tested is how viscoelastic tissues behave when you keep them deformed. Skin, like other soft tissues, doesn’t hold a constant amount of stress forever once you fix its length. Under a constant strain, the internal stress gradually drops as the tissue rearranges and dissipates stored energy over time. This time-dependent decrease in stress is called stress relaxation.

Think of it as the tissue loosening its grip while you hold it in the same position—the initial stress is high, but it relaxes as the structure reconfigures, so less force is needed to maintain the same stretch.

This differs from creep, where the strain continues to increase under a constant load, not the stress decreasing under fixed strain. Hysteresis describes energy loss during a loading-unloading cycle, shown as a loop on a stress-strain graph, and elastic rebound is the rapid return to the original shape after removing the load.