Figure 1. Stress-deformation curve. 1) Initial region (toe region): the curve describes the behavior of the tendons under low deformation (up to 3%), with interweaving of the collagen fibers. 2) Linear region (elastic behavior): the tendon deforms in a linear manner due to intermolecular sliding of the triple helixes of the collagen. If deformation is less than 5%, it proves reversible. 3) Yielding and failure region (plastic behavior).