FIGURE 4.

Energy stored in the tendon for similar elongations is lower in models with greater subtendon twist. (A) The total energy stored in each twist type was calculated longitudinally using two methods. Full tendon stored energy was calculated by integrating the force (F) from all subtendons over the average length change (ΔL) of the all subtendons. Summed-subtendon stored energy was calculated by integrating the force (F) from each subtendon over the average length change (ΔL) of that subtendon then summing the results. Total strain energy was also computed using the strain energy density (Φ) and volume (V) of each element. Colored bars show the proportion of energy stored in each subtendon. (B) The average tendon length change is plotted with the total force in black and the area under the curve was calculated to find full tendon stored energy. Subtendon length changes and forces are plotted with colored lines and area under each curve was summed to compute the summed subtendon stored energy. (C) Posterior and anterior view of each model show the strain energy density (Φ) from each simulation, which was multiplied with element volumes and summed to calculate total strain energy.