The density of the healthy, catabolic and EPOR-active chondrocytes (C(r, t), ST(r, t), SA(r, t)) at t = 2, 4, 6, 8, 10 days with ε = 0.6 and σP = 4.2 · 10−5 (medium strain with low EPO production). We see that with medium strain our penumbra (the region dominated by ST and SA) has widened compared to the low strain case, constituting a potentially larger lesion.