Figure 1  .

(A) Schematic presentation for the indentation measurement setup. (B) A typical series of four consecutive indentation stress relaxation steps (3 µm for each step with ramping speed of 1 µm/s) causing a total strain of 24% in mouse humerus articular cartilage (full thickness about 50 µm). After 200 s of relaxation the next step was taken. (C) Equilibrium stress-strain curve and determination of indentation stiffness from the stress-strain slope.