The effective foot length ratios (EFLRs) of the feet tested in this study ranged from 0.83 to 0.88.
We did not find a significant difference in this outcome, perhaps because of the reasons mentioned earlier (long EFLRs for all feet tested, observed knee flexion with use of more flexible feet).
The increase in prosthetic EFLR was as high as 23 percent of the foot length with decreasing forefoot flexibility (p < 0.001), supporting hypothesis 2.
The EFLR results support this idea, with larger differences between F1, F2, and F3 compared with the differences between F3, F4, and F5.
We believe that the EFLR (the forefoot lever arm) of the different feet is critical in determining sound limb loading.