“…7,8 The initial strain-stiffening phase, or ''toe-in'' region, occurs at low loads and is attributed to progressive recruitment of collagen fibers: due to straightening of slack fibers and rotation of collagen fibers to align with the direction of elongation. 1 When strained, skin dissipates elastic energy stored in the fibrous network via viscous means, as shown through both creep and stress relaxation.…”