Figure 10. Simulation of pharmacodynamic modeling of the concentration versus effect relation in the foot and hand. The top panels show the true relation, given in the discussion. The middle panels show the relation estimated using concentrations sampled one unit away from the site of injection. The bottom panels show the relation estimated using concentrations sampled five units away from the site of injection. The closer the samples are to the injection site, the higher the apparent concentrations, resulting in decreased apparent potency (higher Ce50) of the drug.