Fig 3. Trajectories of the center of mass of four cells with different average speeds.

Four different cells from the experiment are tracked and the resulting center of mass motion is plotted over 500 s. Four different numerical simulations of cell motion are performed and the center of mass motion is calculated and plotted over 500 s. The four numerical simulations are done with the parameter values k_a = 2, k_a = 3, k_a = 4, and k_a = 5 corresponding to the average speeds used in the figure legend.