The metatarsal bones are normally arranged as a parallel series, with the first metatarsal being thicker and stronger than the others, thereby providing a weight-bearing foot. Furthermore, it becomes the fulcrum on which the body weight is swung forward during walking, with its head lying more in an anterior plane than the others. The other important weight-bearing points are the fifth metatarsal and the calcaneus, and these with the first metatarsal head are regarded as the three points of the tripod.
Iyer, K. M. (2013). The great toe. In Orthopedics of the Upper and Lower Limb (pp. 151–168). Springer-Verlag London Ltd. https://doi.org/10.1007/978-1-4471-4447-2_13