Figure 2
Overall (a) and compartmental (b,c) compressive strain (mean, 95% confidence interval) in tibial cartilage as a function of walk duration, for a fixed normalized walking speed (Fr = 0.25); sample size (n) = 10 for all time points except 60 min where n = 8; compressive strain significantly increased (Spearman correlation, p < 0.05) with increasing walk duration in a nonlinear fashion (lines represent the nonlinear mixed effects model fits of the Kelvin-Voigt two-parameter creep model to the duration data while shading represents the 95% prediction interval for the median of this fit).
