Figure 2.

(a) Stress-time plot showing loading regimen of applied vacuum. (b) Stress-deformation plot showing stiffness measured as the slope of the straight-line portion and energy measured as the area under the plot. (c) Deformation-time plot with laxity measured as initial deformation produced by low stress, elastic deformation being the deformation accumulated at the end of vacuum application, creep (A) representing viscous deformation occurring while vacuum is held constant and recovered deformation (B) as the amount of deformation recovered over 3 s following vacuum release. Percent laxity is calculated as laxity divided by elastic deformation times 100. Percent elasticity is calculated as recovered deformation divided by elastic deformation times 100.