Department of Anthropology, Boston University, Boston, MA 02215, USA.
Am J Phys Anthropol. 2013 Jul;151(3):495-9. doi: 10.1002/ajpa.22287. Epub 2013 May 17.
The absence of a midtarsal break has long been regarded as a derived feature of the human foot. Humans possess a rigid midfoot that acts as an efficient lever during the propulsive phase of bipedal gait. Non-human primates, in contrast, have a more mobile midfoot that is adaptive for tree climbing. Here, we report plantar pressure and video evidence that a small percentage of modern humans (n = 32/398) possess both elevated lateral midfoot pressures and even exhibit midfoot dorsiflexion characteristic of a midtarsal break. Those humans with a midtarsal break had on average a significantly flatter foot than those without. Midtarsal breakers also had significantly more medial weight transfer (pronation) during the stance phase of gait than those without this midfoot mobility. These data are in accordance with Elftman (Clin Orthop 16 (1960) 41-45) who suggested that pronation aligns the axes of the transverse tarsal joint, permitting elevated midfoot mobility.
中跗关节缺失长期以来被认为是人类足部的一个衍生特征。人类拥有一个刚性的中足，在双足步态的推进阶段充当高效的杠杆。相比之下，非人类灵长类动物的中足更灵活，这对于爬树是适应性的。在这里，我们报告了足底压力和视频证据，表明一小部分现代人（n=32/398）具有较高的外侧中足压力，甚至表现出中跗关节骨折的中足背屈特征。那些有中跗关节骨折的人平均足部更平。中跗关节骨折者在步态的站立阶段也有明显更多的内侧体重转移（旋前），而没有这种中足灵活性的人则没有。这些数据与 Elftman（Clin Orthop 16（1960）41-45）的观点一致，他认为旋前使横跗关节的轴对齐，允许中足的高度灵活性。
