Table 2.

Testing Conditions / Artifacts Summary for Uniaxial Testing

Testing Condition/Issue	Effects
Straightening curved specimen	Unbuckling/loading of fibers, deviation from physiologic geometry of tissue/fibers, creation of points/regions of stress concentration
Cutting sample	Disruption of natural tension and orientation of fibers, creation of points/regions of stress concentration.
Gripping technique	Non-uniform stress distribution (particularly around grips), restriction of lateral contraction, tissue slippage, realignment of fibers (along loading axis)
Saint Venant’s Principle	Disruption in load distribution; non-uniformity in load transfer from grips to tissue
Anisotropy	Increased apparent variability (may be sign of anisotropy—the direction of sample loading affects representation/generalizability of extracted properties)
Zero-stress state*	Increased apparent variability (Load-deformation variability affected by definition and consistency of initial no-load state of tissue, particularly affected is “toe” region, where slight changes in load are associated with large increases in deformation)

^*Indicates that whole globe inflation is also affected.